• Flashing yellow traffic signals
• Four-way stops
• Look before crossing intersections
• Right-of-way when changing lanes
• Stopping for school buses
• Traffic signals out
• Turning on red
• Waiting in intersections
• Yield vs. Stop
• Yielding on frontage roads
• Yielding to and passing emergency vehicles

• Center left turn lanes
• Changing lanes in an intersection
• Crossing over medians and private property
• Flashing yellow traffic signals
• Four-way stops
• Look before crossing intersections
• Traffic signals out
• Turn signals in a turn-only lane
• Turning from and into the correct lane
• Turning on red
• Waiting in intersections
• Yellow traffic signal (meaning of)

• Center left turn lanes
• Driving on the shoulder
• Turn signals in a turn-only lane
• Turning from and into the correct lane
• Turning left across a median
• Turning on red
• U-turns

• Flashing yellow traffic signals
• Traffic signals out
• Turning on red
• Yellow traffic signal (meaning of)

• Hazard lights while parked illegally
• Parking vs. Standing vs. Stopping
• Parking facing the wrong direction
• Parking in front of fire hydrants

• Crossing over medians and private property
• Don't backup on the freeway
• Drive right, pass left
• Move minor accidents out of traffic
• Right-of-way when changing lanes
• Stopping on entrance ramps
• Yielding on frontage roads

• Passing a funeral
• Stopping for school buses
• Yielding to and passing emergency vehicles

• Advisory speeds
• Flashing yellow traffic signals
• Four-way stops
• Lane markings
• Traffic signals out
• Yellow traffic signal (meaning of)
• Yield vs. Stop

• Driving with parking lights

Some lane markings seem to confound drivers. For example, many drivers don't realize the difference between white and yellow lines. So, without further ado, here are the definitions of lane markings in Texas:

	YELLOW LINES: Traffic going opposite directions is separated by yellow lines. If you're to the left of a yellow line and you're not intentionally passing somebody, you'd better get over to the right FAST before you see the head ornament of a Mack truck directly in front of you. I see this confusion happen a lot when city folks get off on a rural, two-way frontage road. There are various types of yellow lines; see below for the specifics of each.
	SOLID DOUBLE YELLOW LINES: Double yellow lines indicate that passing is not permitted (in other words, a "no passing zone".) Even if you think you can see far enough ahead, there may be some other hazard or reason that you can't see that makes it unsafe for you to pass. However, it is legal to turn left across a double yellow line (with one exception; see sidebar below.)
	SINGLE SOLID YELLOW LINE: This is used to mark the left edge of the roadway on a divided highway or separate the left shoulder from the through lane. The use of this marking to mark the center of a two-way road is non-standard and has no official meaning.
	SOLID YELLOW LINE ON YOUR SIDE, BROKEN YELLOW LINE ON THE OTHER: You may not pass when there is a solid yellow line on your side. Traffic on the side of the road with the broken (dashed) line is allowed to pass. Two sets of these, with the broken lines facing each other, are used to demarcate two-way center left turn lanes.
	BROKEN YELLOW LINE: A single broken (dashed) yellow line means that passing is permitted in both directions.
	BROKEN DOUBLE YELLOW LINES: This marking is fairly rare and is used to separate reversible lanes (i.e. lanes that can change direction.) Pay attention to and obey the lane control signs or signals.
	WHITE LINES: These separate traffic going the same direction. There are several varieties of white lines; see below for the meanings of each.
	DOUBLE WHITE LINES: Parallel white lines indicate that changing lanes or turning across the lines is prohibited. Doing so may be dangerous or interrupt the smooth flow of traffic. In Texas, you'll most often see these where an exit ramp continues into its own lane on the frontage road (see the "Yielding on frontage roads" section below.)
	SINGLE SOLID WHITE LINE: This is used to channelize traffic and indicates that changing lanes is discouraged, although not specifically prohibited. You can cross it if you have to, but you should avoid it if possible. Even a thick single white line can be crossed if necessary; however, they are really discouraging you from crossing, so you should think twice about it. Note that there is an exception; see below. A single white line is also used to mark the right edge of the roadway or separate the right shoulder from the through lane.
	BROKEN WHITE LINE: A broken (dashed) white line separates lanes of traffic traveling in the same direction.
	SHORT BROKEN WHITE LINE: A short broken (dashed) white line marks a lane that will soon become an exit or turn-only lane. Short broken lines are also used to mark lanes through an intersection.

Crossing a single white channelizing line
In the explanation above, it is noted that crossing a single white line-- even a thick one-- is allowed. However, there is an exception to that-- the channelizing island. This is when there are two single white lines that are converging or diverging in a roughly triangular shape. The area between the lines in this case is known as a "neutral area" in which vehicles are not allowed because crossing it interferes with the smooth merging or diverging of traffic. (As a footnote, engineers call this area the "theoretical gore". The "gore" is that triangular area of grass or concrete island that comes to a point where the pavement merges or diverges. The "theoretical gore" is the area of pavement that would be grass or concrete island If the gore were extended to its maximum extent.)

Turning left over double-yellow lines
A big misconception in the arena of lane markings is the meaning of the double-yellow line with regards to left turns. A double-yellow line simply means "no passing"; it does not prohibit left turns. In fact, you are specifically permitted by statute to turn left over double yellow lines:

Lots of folks have questions as to just what a yellow light really means. By law, a yellow light is simply a warning that the light is about to change to red. Technically, since no conflicting traffic can have a green while you have a yellow, you still have the right-of-way-- it's really just an extension of the green but letting you know that the green is ending. Therefore, you are still allowed to cross the stop line or crosswalk when the light is yellow, and as long as you have done so before the light turns red, you have not violated the law.

Now, does this mean you should race to beat the red-- no, of course not. If the light is yellow and you have not passed the "point of no return" and can safely stop, you should do so. Note, however, that I said "safely" stop. If the road is wet and you don't reasonably think you could stop without sliding into the intersection or perhaps having the guy in back slide into you, then keep going (carefully, of course)-- your duty to prevent a crash is foremost.
 

Most traffic signals will default to a flash mode as a fail-safe measure if there has been a malfunction or power outage and the signal did not properly reset. Some signals also go into flash mode during overnight hours, and brand new signals are typically run in flash mode for a few days before being fully activated (this is done to burn in the electronics as well as to give regular commuters notice that the signal will be activated soon.) In some cases, the signals will flash red for all directions, but in many cases, the main road will get a flashing yellow while the minor road will get a flashing red.

Here are two common questions related to legal turns on red.

Left on red
Whenever I drive downtown, I often end-up stuck behind someone on a one-way street stopped at a red light waiting to turn left onto another one-way street with no traffic coming. If only they knew that they were wasting their time (and mine) sitting there. A left turn on red (after first stopping) is allowed when the street you are is one-way and the street you are turning onto is also one-way (to the left, of course). Makes sense if you think about it-- it's just a mirror image of a right on red.

There are a handful of states that allow a left on red from a two-way to one-way street, but Texas does not. Unless both streets are one-way, you can not make a left on red. Also, there are some who believe that you can make a left on red if there are no signs such as "LEFT TURN SIGNAL" or "LEFT ON GREEN ARROW". Again, not in Texas. Those signs are purely informational and as long as a signal is obviously intended to regulate traffic turning left (which a red arrow or signal to the left of green signals for through traffic would be), then drivers are required to obey it regardless of the absence of any signs. Turning left on a red light, unless both streets are one-way, is running a red light and you can be ticketed for such.

Right on red from double turn lanes
In a related matter, I often get the question of whether it is legal to make a right on red from both lanes when there are double or dual right turn lanes. The law simply states that you can turn right on red after stopping; it doesn't specify which lane(s) it applies to. So, if you can legally turn right from a lane, you can legally turn right on red from that lane so long as there aren't any signs prohibiting it such as those shown below.

The issue of waiting in an intersection is a little tricky. The law specifically prohibits stopping in an intersection. However, subsection (f) of the same law makes an exception "if the avoidance of conflict with other traffic is necessary." Therefore, the following sections cover the two conflicting issues regarding when to wait in an intersection. Paradoxically, many people do exactly the opposite of these.

• First of all, don't do this if the street you want to turn onto is congested and backed-up to the intersection or nearly so (see "Don't block intersections" below.)
  
  
• Secondly, if you're still in the intersection when your light turns red, make sure that the oncoming traffic is stopping before you actually turn-- sometimes someone will be trying to beat the red.
  
  
• Finally, sometimes oncoming traffic will still have a green even when your direction has a red. In these cases, there is supposed to be a sign that reads "ONCOMING TRAFFIC HAS EXTENDED GREEN", but I honestly have never seen one. If there is such a sign, you should wait behind the stop line. This doesn't happen with a flashing yellow arrow which was developed specifically to eliminate this hazardous situation.

Where to wait to turn left

Don't block intersections
If the street you are on is bumper-to-bumper and you come to an intersection with a green light, remember: "Don't Block The Box!" You should not enter an intersection if congestion would prevent you from immediately vacating the intersection when the signal turns red. In other words, don't drive into an intersection unless you know you can get out quickly if the light turns red. So why doesn't the exception provided by subtitle (f) apply? In this case, you're not stopping to avoid conflicting with other traffic, you're stopping due to congestion, which is different. It's basically a matter of common sense and good faith in keeping with the spirit of the law. With the left-turn rule above, assuming there is nothing obstructing the street you want to turn onto, you will be able to vacate the intersection before or immediately after your light turns red and therefore won't be blocking the intersection for cross-traffic. With congestion, your egress is blocked by stopped traffic which will prevent you from being able to exit the intersection immediately when the light turns red and thus will leave you blocking the intersection for cross-traffic.

By the way, this rule can also cancel the waiting-to-turn-left rule above: if you have a green light, or even a green arrow, but the street you want to turn onto is backed-up to the intersection, wait behind the stop line or crosswalk until there's room for you on the other street, then turn.

New York City had such a problem with blocked intersections that they started a public education program called "Don't Block The Box!", and several Texas cities have now adopted it as well. Obstructing intersections in this manner causes traffic on the intersecting street to also become congested. This leads to the phenomenon known as "gridlock" where several blocks of traffic in all directions are "locked" because of obstructed intersections.

Yield on green
Even if you have a green light, the law requires you to yield to traffic already in the intersection. So if someone on the cross street was hanging-out in the intersection waiting to turn left when your signal turns green, don't roar into the intersection and pound your horn-- they're legally there and have the right to make their turn unmolested and you're just being a putz by not giving them a few seconds to move on.

Additional information
Several people have written me saying that §545.056 does in fact prohibit changing lanes in an intersection. However, they are incorrectly interpreting the statute. Here is the text of that statute:

Notice that the statute specifically says "an operator may not drive to the left side of the roadway". This is different than the changing lanes discussed above. "Changing lanes" is when there are two or more lanes for the direction you are traveling (i.e. they're marked with a white dashed line) and you wish to change between those lanes. "Driving to the left side of the roadway" is just that-- going across the yellow line down the middle of the roadway and crossing into oncoming traffic. As you can see by the statute, doing this is illegal within 100 feet of the approach of an intersection. My guess is many people misconstrue or misremember this rule to mean that you can't change lanes at an intersection. However, the two are completely separate things; there is no restriction on changing lanes.

It's been widely reported by numerous school districts and police agencies that many drivers either have no clue about the requirement to stop for school buses, are simply are not paying attention, or frankly are in too big of a hurry to stop (I hope it's not that last one, although in this day and age, it's certainly possible.) The law is simple: if you are approaching a school bus that has stopped and its red lights are flashing, you must stop. Most school buses also have one or more stop signs on the driver's side that swing out to remind you of your duty to stop.Traffic heading in both directions is required to stop and the requirement to stop applies in both urban as well as rural areas.

Once you have stopped, you are required to remain stopped until the lights stop flashing, the bus has started moving again, or the driver waves you to move on.

Note that in Texas traffic code, the term "highway" is defined to mean any public roadway, including city streets (§541.302).

Exceptions
There are a couple of exceptions to the requirement to stop. One is if there is a median, island, or physical divider between you and the school bus; in those cases, you can proceed, but I recommend that you do so cautiously in case any kiddos are crossing carelessly (it's been known to happen.) Note that the law specifically indicates that a left turn lane does not count as a divider-- this means that even on a street with three lanes in each direction plus a center turn lane, traffic in all seven lanes must stop for a school bus. (The reason for the difference is that an island provides a safe place for pedestrians to wait for a break in traffic while a left turn lane doesn't.) There is also an exception for when a bus is stopped in a loading zone on a controlled-access highway (i.e. a freeway), but that seems to be an "old school" artifact (ha, see what I did there?) as I have never actually seen one of these.

Intersecting streets
A common question is whether you have to stop if a school bus is stopped at an intersection but is on the intersecting street, i.e. is not on the same street you're on, and you're traveling straight through or turning away from the bus. The law is not clear on this. However, the statute reads that you have to stop "when approaching from either direction." This would seem to indicate that you have to be moving toward the bus from the front or rear. If the bus is on a different roadway than you, you're not really approaching it from either of those directions. Furthermore, it says drivers "shall stop before reaching the school bus", but if you're on an intersecting roadway, you would never "reach" the bus. Finally, the title pretty much indicates the intent of the statute-- that drivers may not pass a stopped bus. Again, if you're on an intersecting roadway, you would never "pass" the bus.

Given all of that, it appears the law does not require you to stop in this situation. That said, if the bus is at or in close proximity to the intersection, and you're not on a major thoroughfare (where stopping unexpectedly poses a hazard), it's probably a good idea to stop, if not for legal reasons, then certainly for safety-- especially if there are kids who look like they might want to cross your street. If you do chose to proceed, do so with extreme care.

Now, if you're approaching a school bus stopped across an intersection from you on the same street and you wish to turn before reaching the bus, that's even less clear.  In that case, it's probably best to stop.

As a footnote, I've seen some school bus drivers who will stop their bus in the intersection to make this all a moot point, and some stops are located mid-block to avoid any such issues.

School buses with hazard flashers on
School buses are required by law to stop at all railroad crossings. (That, BTW, was the subject of the bill in School House Rock's "I'm Just a Bill" song.) When they do this, they usually switch on their hazard flashers to warn traffic behind them of the impending stop. You are not required to stop for the bus in this case (unless you are directly behind them, of course.) You are only legally bound to stop when the alternating red lights at the top of the bus are flashing.

It should also be noted that sometimes when discharging or boarding passengers, the driver may determine that there is not a need to stop traffic, for example, when stopped in a loading area in front of a building, and will only activate the bus's hazard flashers. Again, in this case, you are not required to stop; however, you should proceed with extreme caution.

Yellow flashing lights
Finally, most school buses also have yellow alternating flashing lights next to the red ones. The meaning of these lights confuses many drivers. In short, these are used to warn drivers that the bus is about to stop, much like a yellow traffic signal warns that the red is about to come on. You are not required to stop when the yellow flashers are on, but you should show down and prepare to stop.

Yielding to and passing emergency vehicles

The purpose of the first law quoted above is obviously to give emergency vehicles a clear path, and the reason they need that right-of-way is also obvious. Think of it like this: if you or a loved-one needed help and called 911, wouldn't you want everyone to make way for those emergency vehicles?

As the law says, you are required to pull-over to the right-hand side of the road and stop. This law applies no matter which direction you are traveling relative to the emergency vehicle. Also, needless to say, give emergency vehicles the right-of-way at all intersections, even if they would normally have to yield to you (see "Look Before Crossing Intersections" above.)

The second law requires drivers who are approaching an emergency vehicle stopped on the road with their emergency lights flashing to do one of two things: move out of the lane nearest the emergency vehicle or slow down to 20 miles per hour below the posted speed limit (down to a minimum of 5 mph). In other words, if you're going down the freeway in the right lane and there's an emergency vehicle parked on the right shoulder ahead, you should immediately move into the next lane to the left. If you can't, or if you're on a road where there is no extra lane to move over to, then you must slow down to 20 mph below the posted limit. The purpose of this law is to give emergency workers a safe area to work in when they're on or near the road.

The "move over" law was updated in 2013 to include tow trucks and TxDOT vehicles, and again in 2019 to include utility and garbage trucks.

Emergency vehicle behind you at a traffic signal
If you're stopped at the head of the line at a red light and an emergency vehicle with its lights flashing and siren sounding is behind you and can't get through or around the traffic, then you should first try to make room for them if at all possible by scooting over. If that is not possible, then you should consider running the red. The law does not specifically require or allow this, but the spirit of the law dictates that the right-of-way of the emergency vehicle takes priority over the traffic signals. Before you go through the red, though, make sure it is absolutely safe to do so. In most cases, cross traffic will see your predicament and stop, but if not, nudge slightly into the intersection as a signal to other drivers but wait until it is safe before you cross. Then, go through the intersection, pull over and stop. A safer alternative would be to turn right, but again, only when it is clear to do so.
 

You'd think most people would have enough common sense to know not to park in front of a fire hydrant, but I see it done all the time. In case of a fire, the fire department needs to be able to find and access hydrants quickly. If you're parked in front of it, it obstructs them and delays their response to a fire. Would you want someone blocking the fire hydrant nearest your home if it were on fire? (Footnote: Remember the scene in Backdraft where the firefighters break the windows of a car parked in front of a hydrant and run the hose through the car? Apparently, from the photo below, it happens in real life as well.)

Don't let this be you!
 

The terms "no parking", "no standing", and "no stopping" are not well-understood and often conflated.

No stopping is the most restrictive-- you cannot stop there even briefly for any reason except if you have to because traffic has stopped, you need to stop to avoid hitting a pedestrian or another vehicle, or a police officer directs you to stop.

As for no parking and no standing, the difference basically boils-down to whether or not you're loading or unloading people or stuff. If you stop for a passenger to get in or out, that's standing. If you stop to load or unload cargo, that's parking. To help summarize the differences, I've created this handy-dandy reference table that shows what's allowed and not allowed in each situation:

Loading/unloading passengers
Loading/unloading cargo

• No parking or standing in front of a fire hydrant (see section above)
• No parking or standing within 30 feet on the approach to a stop or yield sign or traffic signal
• No parking or standing within 20 feet of a crosswalk (marked or unmarked) at an intersection

When parallel parking on a street, it is illegal to park facing oncoming traffic. Lots of folks do it, though, especially in residential neighborhoods. But it's illegal because it's generally unsafe for several reasons.

First of all, to park facing traffic requires one to drive on the wrong side of the street, which is illegal unless overtaking another vehicle or passing an obstruction. And in doing so, pedestrians, cyclists, children, or other motorists are not expecting you to be coming from that direction on that side of the street and may enter the street without looking for you.

Secondly, all cars have reflectors on the rear, but the front of most cars do not have reflectors, so when parking at night, a vehicle facing the wrong way is less visible, especially in low-visibility conditions. And parking the wrong way may cause someone approaching your vehicle in low-visibility conditions to misinterpret which side of the road it's on and attempt to go around it on the wrong side.

Also, when leaving a parking space faced the wrong way, you have to clear traffic from both directions, a more complicated task, especially from a parallel position.

Finally, when you are parked the wrong way and another vehicle parks in front of you-- especially one that is larger-- your view of traffic will be obstructed since you will be seated at the curb side instead of on the traffic side. Therefore, you will not be able to see oncoming traffic until your vehicle is most of the way into the traffic lane, thus creating a hazardous condition.

But, you say, you park where someone won't park in front of you. Yes, then in that case, this specific reason wouldn't apply. However, the law does not provide that exception, and for good reason-- sure, maybe there's not a place to legally park in front of you. But what if a car broke down there? Or someone parked illegally there? Not to mention that the other safety reasons mentioned above still apply. So take the extra 30 seconds to turn around and park facing the right way.

Many people who park someplace they shouldn't in order to briefly run inside will switch on their hazard lights (flashers) to indicate that they're parking for "just a minute" and that they'll be right back. Some even believe this legalizes what they're doing.

It doesn't.

If the sign says "no parking", then that means no parking. It doesn't mean "no parking except for a minute or two" while you run into the store, restaurant, etc. If that's what they meant, then the sign would say that. Switching on your hazards doesn't magically exempt you. In fact, most parking enforcement officers say that a car with its flashers on is a beacon to them that the car is parked illegally and tells them that the driver knew they weren't supposed to park there.

This tells parking enforcement officers "come give me a ticket!" 

First, let's talk about the law in this situation. The law requires you to use all your lights (including headlights) at nighttime, which is defined as being one half hour after sunset to one half hour before sunrise, as well as any time when you cannot see clearly for 1,000 feet, which essentially covers all inclement weather as well as dusk and dawn. Therefore, you should never be driving with just your parking lights on. If you're in a situation where you need to have any lights on at all, then you must use all your lights, which includes your headlights.

Some people will say that they don't want to use their headlights during bad weather or at dusk because there's enough ambient light for them to see and their headlights won't be illuminating anything. However, headlights are not only for lighting-up the road ahead for you to see, but they also make you more visible to other drivers. Headlights are visible at a greater distance than parking lights alone. This is why motorcycles and emergency vehicles always use their headlights and is also the rationale behind daytime running lamps (see below for more discussion on DRLs.) So whenever visibility is reduced, you should use your headlights, if not to help you see but to help others see you.

Others may argue that using their headlights puts a strain on their electrical system or battery. This is simply not true. Your vehicle's electrical system is designed to operate all of the vehicle's electrical devices, including the headlights. Your battery is only used to start your car and to power electrical devices in the car when the engine is not running. When your engine is running, the alternator, which is cranked by the engine, is providing power to your vehicle as well as recharging your battery. If using your headlights does indeed cause electrical problems for your car, then your car is unsafe and needs repair.

So what are parking lights for then? They're mostly a relic from before hazard flashers were common. Their purpose was to give your car visibility while stopped on the side of the road. They're essentially obsolete now and many manufacturers have eliminated them.

Parking lights vs Daytime Running Lamps
Note that parking lights are not the same as Daytime Running Lamps. Parking lights are when you can activate the front and rear marker lights without turning-on the headlights (see the photo below for an example.) These are intended to make your vehicle more visible while it is parked on the side of a dark road, thus the term "parking lights". However, as discussed above, parking lights are mostly obsolete nowadays and many recent-model vehicles in the United States are no longer equipped with them. For vehicles that have parking lights, there is typically a third setting or position on the headlight switch-- position 0 is off, position 1 is the parking lights, and position 2 is all the lights including the headlights. Daytime running lamps are essentially the opposite of parking lights-- they're the headlights illuminated with the front, rear, and side marker lights off and are generally automatically controlled. Some vehicles use a completely separate set of lamps instead of the main headlights for the DRLs. Wikipedia has a good write-up on the differences at http://en.wikipedia.org/wiki/Automotive_lighting.
 

Parking lights
 

It might seem logical that if you are in a turn-only lane, you don't need to signal your turn. As you can see above, however, the law is quite straightforward-- you must use a turn signal any time you want to turn or change lanes. There is no exception for turn-only lanes. The reason is simple: while it may be obvious to you and to the guy behind you that you are in a turn-only lane, it may not be evident to motorists or pedestrians across the intersection or on the intersecting road. Using your turn-signal clearly indicates to everyone who may need to know that you are are going to turn.

Some states waive the requirement to use turn signals if no other vehicles are in the vicinity, but Texas has no such exception. You don't know what you don't know, so you should always signal in case there's someone nearby you don't see.

Imagine you are on a street approaching an intersection with lanes marked like the right hand illustration above. Recently, I have seen an increasing number of people turn from the two center lanes. BUZZ! Unless there are signs and/or lane markings indicating otherwise, the law only allows you to turn left from the far left lane or to turn right from the far right lane. When there are dedicated turn lanes like those in the right hand example above, those lanes fulfill those roles. So, for example, if you wanted to turn right from the right hand through lane (i.e. the lane immediately to the left of the right-only lane), you would only be permitted to do so if it was marked as shown in the right hand illustration below.

OK, now that we know which lane to turn from, we need to know which lanes we can legally turn into. In Texas, when turning right, you are required to turn both from the right lane (as discussed above) and into the right lane unless there is an obvious safety reason not to (e.g. you're driving a long vehicle or there is a pedestrian or debris in the road) or, of course, if there are signs are markings indicating otherwise (e.g. a double turn lane.) When turning left, however, you are permitted to turn into any lane designated for traffic headed in that direction and it is recommended that you pick the lane that interferes least with other traffic. The exception is if you're turning left from a one-way street onto another one-way street; in that case, you must turn from and into the left lane (i.e. the mirror of a right turn.) Also, if you are turning from one of two lanes designated for the same turn movement (i.e. double turn lanes), then you must turn into the appropriate lane as indicated by signs and/or pavement markings. And one final word: keep in mind that other people may not always follow the law, so be prepared to yield if necessary, even if you're in the right.

Extra tip
Good driving habits dictate that you turn into the lane nearest you, so, if you're turning left, you should turn into the left lane if possible.
 

As you can see above, the law for the use of center two-way left turn lanes is pretty much non-existent. The statute above is the only one that pertains to center lanes, and other than allowing its use for left turns, doesn't give any restrictions on how it can used for that.

Before we move on, now would be a good time to point-out that while section (b)(1) above says you can use a center lane for passing, keep in mind that center lanes marked as left turn lanes cannot be used for passing as the traffic signs and pavement markings take precedence. Section (b)(1) really is an artifact from days long ago where so-called "suicide lanes" were used on rural roads to allow passing in either direction; fortunately, those lanes are pretty much all gone now and have been replaced by dedicated passing lanes for one direction or the other. Section (b)(3) would apply in that case or also in the case of reversible lanes.

Regarding center two-way left turn lanes (TWLTL), if the law doesn't specify how it is to be used, then where is that defined? For starters, the Texas DPS driver's handbook states, "the only time a vehicle should enter the center (turn) lane is at a point where the vehicle will have time to slow down or stop in order tomake a safe left turn maneuver. The center turn lane should never be used for passing or as a through traffic lane. " That explanation is based on the Texas Manual on Uniform Traffic Control Devices (TMUTCD), which as mentioned elsewhere on this page has statutory authority for the definition of signs and markings. The TMUTCD states that a lane marked with the sign to the left and the standard TWLTL markings (a solid yellow line with a broken yellow line to the inside) "is reserved for the exclusive use of left-turning vehicles in either direction and is not used for passing, overtaking, or through travel."

So with that said, there are many questions that arise that are not directly answered by the statute or TMUTCD. Probably the top one is, how far before turning can you legally enter this lane? Again, there is no defined statutory limit. Furthermore, each situation is different and can vary depending on the speed of the vehicle, weather and traffic conditions, the presence of an oncoming vehicle in the lane, etc. Drivers must use their best judgment and not enter the lane too early or they may be perceived as using it as a through or passing lane. Police officers also have to use their judgment in enforcement and this difference in what may be considered "too far" often results in a citation. The general guidance is to not enter the lane until just before you need to slow down to either stop or complete your turn. This will vary depending on your speed and the presence of other vehicles int the TWLTL.

Another common question is whether you may use a TWLTL that feeds into to a regular left turn lane at an intersection in order to pass traffic stopped in the through lanes if you want to turn at the intersection. Again, the law does not address this maneuver. If you use it to pass the stopped traffic for a relatively short distance, then you're not likely to get cited. But if you're passing a long line of vehicles, passing no vehicles, or passing vehicles that aren't stopped, then you could get cited, especially if you're whizzing by at a high rate of speed or your action interferes with someone wanting to make an opposing left turn. The upshot: I would avoid doing it for more than a couple hundred feet or so.

Finally, one other common question is whether you can use the TWLTL to wait or merge when turning onto the main road from a side street or driveway. Once again, the law and TMUTCD gives us no guidance on this. However, the Federal Highway Administration's "Read Your Road" guide, which humorously calls the TWLTL a "special place", states that, when turning from a side street or driveway onto the main road, you may use this lane as "a safe mid-point to wait for a gap in traffic approaching from the right before completing your turn." However, it is important to note that since Texas law makes no provision for this action (nor does it specifically prohibit it for that matter.) However, since the signage and markings indicate it is a left turn lane from the main road, any other use would not conform to that, and I have had reports that drivers have been cited for doing this and the court has upheld their citation. Therefore, I would recommend avoiding this maneuver unless absolutely necessary, and if you do, do not under any circumstances use the center turn lane as an acceleration lane! Instead, wait until there is an opening in the traffic and then move immediately from the center lane into the through lane.

One final note: Some municipalities have ordinances that more specifically regulate the use of TWLTLs. For instance, the City of Cleburne specifically states a TWLTL can only be used by drivers when preparing to turn from said lane, and you're not allowed to drive in a TWLTL for more than 200 feet. 

How to turn left when median is 30 feet wide or wider ("wide median")

How to turn left when a median is less than 30 feet wide ("narrow median")

• If a median is 30 feet wide or more, there will usually be yield or stop signs in the median, a set of double-yellow lines, and stop or yield lines; these are your cue to treat it as a wide median (top example above).
  
  
• If there are no stop or yield signs or lane markings in the median, then that is generally your cue to treat it like a narrow median (bottom example above.) In these cases, there is often (but not always) a "keep right" sign on the median nose. Also, signalized intersections should usually be treated as a narrow median regardless of width.

It is illegal to drive across any median. This includes the median between the freeway and the frontage road-- even when there's a traffic jam on the freeway. If you want to get onto the frontage road, get off at the next exit. Crossing medians is rife with hazards to you, your car, and other drivers, and many times you won't gain much if any advantage doing so anyway. Also be sure to see the section about "flush median islands" in the lane markings section above.

Similar to driving across the median, it is also illegal to cross private property for the purpose of turning left or right from one road to another. In other words, it's illegal to cut-through that gas station or shopping center on the corner so you don't have to stop at the stop sign or red light or to avoid the line of cars waiting at the intersection.
 

This law is pretty straightforward as written: if you're on the frontage road (aka access road, feeder road, service road, or gateway) of a freeway or expressway, then you must yield to traffic exiting the freeway or expressway and coming onto the frontage road. But there are some nuances that will be discussed below.

Note that yielding may or may not mean stopping (see the next major topic below.)

On all frontage roads, you must yield to traffic exiting the freeway as they are entering the frontage road. In areas with two-way frontage roads, you must also yield to (oncoming) traffic that is entering or about to turn onto an entrance ramp. In those areas, drivers who are not getting on the freeway, but who would have to veer left across oncoming traffic if they were, will often use their right turn signal as a friendly gesture so that oncoming traffic will know they don't have to slow down or stop for them (see diagram below.) If you see this, though, be extra careful as the person may have left their turn signal on from a previous turn and actually wants to enter the freeway. Also keep an eye out for traffic behind them who may want to enter the freeway.

So a question that may come to mind is, how far does the yield requirement extend? On a two-way frontage road, the location of the intersection(s) is generally quite obvious, and so the yield applies there. On a one-way frontage road, however, the angle of the ramp makes it a little more difficult to delineate when traffic is no longer "entering" the frontage road. One way of looking at it is that the yield requirement covers the intersection of the two roadways, which is defined in §541.202 as "the place where vehicles could collide if traveling on roadways of intersecting highways that join at any angle other than an approximate right angle." The diagram below illustrates this. But perhaps an easier interpretation is that once a driver exiting the freeway turns into a lane on the frontage road, they then become established in that lane and are thus no longer entering the frontage road, so the requirement to yield to them ends at that point. Moving from that lane then becomes an ordinary lane change and is subject to the laws that govern lane changes.

Another question is, can traffic exiting the freeway shoot across the frontage road and immediately turn into a driveway? As long as there isn't a double white line (more on that below), then yes, it is technically legal, although strongly discouraged due to the myriad of hazards it causes.

Potential collision points at intersection of one-way frontage road and exit ramp

The double white line exception
This law covers all entrance and exit ramps, even if there are no yield signs. However, there is an unwritten exception: When traffic exiting the freeway has its own added lane that is separated from the other frontage road lanes with a double white line, then no yield is required. This is because the double white line forces exiting vehicles into their own lane on the frontage road and to travel in that lane beyond the intersection of the ramp and frontage road. As discussed above, this means when they reach the point at which they can legally move into the other frontage road lanes, it's just an ordinary lane change at that point and is regulated accordingly (see diagram below.) This configuration was developed to alleviate the congestion on many urban frontage roads that occurred as a result of frontage road traffic having to yield to a nearly continuous stream of exiting vehicles. Eliminating the need for traffic on the frontage road to yield improves traffic flow. This configuration also improves safety because it eliminates the hazards caused by injecting exiting traffic directly into or across the frontage road traffic and helps exiting drivers to adjust to frontage road conditions before moving over. As a result, this configuration is becoming more widespread.

Some people write me to ask for the statute where this exception is granted-- well, as I mentioned above, this is an unwritten exception. Instead, the "exception" in this case is the outcome of the combination of the added lane, double white lines, and the resultant traffic flow. The double white line means that exiting traffic cannot legally conflict with traffic already on the frontage road at the point where the ramp and frontage road intersect. Instead, the double white lines shunt that exiting traffic past the point where they would conflict with traffic already on the frontage road (see diagram above.) As a result, there is no intersecting traffic that would require right-of-way control like there is at locations that don't use this configuration. 

No yield required on frontage road when exiting traffic has its own lane separated by a double-white line

It's worth noting, however, that if you're on the frontage road and cross the double white lines into the exit lane and interfere with traffic exiting the freeway, you could be cited for violating §545.154 in addition to the violation for crossing the double white lines. And if you're exiting and cross the double white lines, that violation would make you at fault for any resulting collision.

Note that there must be a double white line for the exception above to apply. If the exiting traffic has its own lane, but that lane is separated from the others by a single solid white line or a broken white line, then the yield law still applies. This is because in that situation, the exiting traffic is not required to enter the added lane and could immediately cross into any of the other frontage road lanes (see diagram below.) These potential conflicts have resulted in this configuration being deprecated by TxDOT. (See the lane markings section for clarification on why someone can cross a single solid white line.)

Many locations with a double white line also have signs like the one shown here. However, these signs are considered reminders and are not required as the double white lines alone convey the "do not cross" meaning.

Finally, you may happen upon a location with a yield sign and double white lines. In these situations, the yield sign is usually an artifact from a previous configuration before the double white line was added and, due to an oversight, the yield sign was not removed.

Official support
If you desire an "official" confirmation of this interpretation, see the "Frontage Road-Ramp Intersection Control" section of TxDOT's Sign Guidelines and Applications Manual.

Yield required on frontage road when exiting traffic has its own lane NOT separated by a double-white line

There's a reason for having two different signs. "Stop" means that you must come to a complete stop, period. "Yield", however, doesn't always mean that you have to stop. Instead, a yield sign means that you must give the right-of-way to other traffic by slowing or stopping as necessary. You can satisfy the requirement to yield by slowing down enough to let the other guy get through the intersection (and without any angst.) If you can clearly see nobody is coming, then you can just proceed without slowing excessively or stopping. So, if you're approaching a yield sign, start looking early and if the way is clear, just keep going. 

That said, the opposite is also true: if it is necessary to provide a clear path for the other driver, you are indeed required to stop at a yield sign.

Footnote
Unfortunately, in many areas, it often seems that yield signs are placed where there should be stop signs and vice-versa. Europe overwhelmingly prefers yield signs; the US is ridiculously riddled with unnecessary stop signs.

Never, ever back-up on the freeway, even on the shoulder! Besides being illegal, this is extremely dangerous! Traffic is coming toward you at high-speed, and if you're backing-up, you're essentially going the wrong way and risk the equivalent of a head-on collision. If you miss your exit, just drive to the next exit, turn around, and go back. In most cases, you'll only lose a couple of minutes. Next time, make sure you know where you're going and pay attention to the signs.
 

Have you ever been caught in a traffic jam only to find that it was caused by a minor fender-bender blocking a lane and everyone is standing around waiting for the police? Maybe you've thought to yourself, "there oughta be a law..." 

Well, there is. The law requires that anyone involved in an accident not obstruct traffic any more than is necessary. The law even specifically requires that, if an accident occurs on a freeway or freeway ramp in a metropolitan area and all involved vehicles can be safely driven, the motorists involved must move their vehicles off of the freeway immediately. This is to help prevent a traffic hazard and resulting congestion which, besides unnecessarily delaying others, also increases the likelihood of other accidents. Many people think that their insurance won't cover them if they move their cars from the scene before the police arrive, but this is absolutely false. The police and insurance adjusters can usually determine what happened based on the stories of those involved and the damage to the vehicles. Besides, in the case of most fender-benders, you legally don't even need to have the police come to the scene. But if you're worried, then quickly snap some photos of the scene and vehicles with your cell phone camera before you move out of the way.
 

A common question I get, especially for newcomers to Texas, is whether it is legal to drive on the shoulder of a two-lane highway to allow other cars to pass as they have seen people doing. The answer is yes, it is, as declared in (a)(5) above. You'll find that many long-time Texans will automatically move onto the shoulder when a faster car comes up behind them on a two-lane road. It's just a common courtesy and helps the other person to pass them safely. However, there are some requirements to do this-- the shoulder must be wide enough and free of debris or stalled or parked vehicles (it is generally illegal to park on highways outside of business or residential districts). If you do move onto the shoulder to allow someone to pass, reduce your speed a bit, keep a sharp eye out for any obstructions ahead, and move back into the main through lane as soon as it is safe to do so.

You are also allowed to briefly drive on the shoulder to pass a vehicle that is slowing or has stopped in the main lane to turn left or has stalled. Additionally, you can also drive on the shoulder to slow down to turn right, to speed up after turning onto the highway or after having stopped on the shoulder, or to avoid a collision (duh.)

You are not allowed to drive on the shoulder to overtake another moving vehicle (except as provided above). In other words, if the vehicle you are following will not move onto the shoulder to allow you to pass, then you must pass them on the left when it's legal and safe to do so.

Using the shoulder to turn right in heavy traffic
One other frequent question is about using the shoulder to pass a long line of stopped traffic if you want to turn right at a driveway or the next intersection. Section (a)(4) above, on its face, does seem to allow for this. The main sticking point is the phrase "if that operation is necessary". The statute doesn't define what "necessary" is. However, there is case law that addresses this specifically. In Lothrop v. The State of Texas (2012), the Texas Court of Criminal Appeals (which is the supreme court in Texas for criminal cases) ruled that "necessary" had to be taken in context of the seven permissible reasons to drive on the shoulder. In other words, if you have to drive on the shoulder to pass a vehicle stopped in the main lane (as opposed to passing them on the left, for example), then that qualifies as "necessary". 

The other stipulation is that the maneuver be done "safely". Again, the law does not define this specifically, so it's open to interpretation. Typically, if there is no collision, then that could be considered prima facie evidence that it was done safely. A more affirmative defense would be that the driver ensured the shoulder was clear of obstructions and that they drove slowly. (My recommendation would be 20 mph-- if it's considered safe for a school zone, it's certainly safe enough for passing stopped vehicles.)

Many officers I've spoken with tell me that because of the uncertainty of this law, they usually won't cite for this or they will only cite someone who does this egregiously; for example, someone who is racing down the shoulder (which seems to violate the "be done safely" stipulation as discussed above), someone who gets on the shoulder well before the back of the line (because you're not actually passing any stopped vehicles at that point), or someone who continues on the shoulder through an intersection. (Those all seem like good reasons to me to get a ticket.) But some officers and departments will always cite for this and leave it to a judge to decide.

In short, while statutory and case law seems to allow this, it still seems to be a bit of a gray area in some jurisdictions, so YMMV and you should do this at your own risk.

U-turns

Unless traffic on the freeway is completely stopped or you can't merge and there is no place else for you to go, do not ever stop on a freeway entrance ramp! This is an extremely serious traffic hazard. Drivers behind you are speeding-up to get up to freeway speed and are looking back up the freeway for a gap to merge into. They are not expecting you to stop! If you can't squeeze into traffic by the time you get to the end of the ramp, make sure your left turn signal is on and carefully continue on the shoulder (if it's clear) until you can safely merge into the traffic stream.

Be helpful to traffic entering the freeway
If you're in the right lane of a freeway and see traffic preparing to merge, move over or make room for them to merge into. Although the law requires traffic entering the freeway to yield (basic right-of-way law, §545.151), good drivers make the effort to help-out other motorists.

Merging from the shoulder
If you stop on the shoulder to change a flat tire or deal with some other emergency and you're ready to get back on the freeway, get up to speed on the shoulder, then signal left and merge into traffic. Do not pull from a standing stop directly onto the freeway's main lanes. This very action killed a mother and van full of children west of Ft. Worth back in the mid '90s.
 

Before I explain this one, let me ask you this: where is the fastest water in a river? In the middle, of course. Why? Because this is the place with the least friction. This is the deepest part of the river and there are no ragged edges or shallow bottom to slow the water. A highway conceptually works the same way (think of it as a two-way river.) The right lane has the most "friction": entering and exiting traffic, stalled vehicles on the shoulder, etc. The left lane has virtually no friction. That is why it is reserved for faster-moving traffic.

Imagine this scenario: you're in the left lane on the freeway going faster than other traffic and you come up behind someone going a little slower than you. Instead of waiting a few seconds for them to move over, you whip around them on the right. At the same time, someone going much slower than you is trying to get on the freeway at the same location. Now, both of you are creating a big hazard for each other and someone is going to have to give. This is why (a) you shouldn't pass on the right; and (b) you should move to the right if you're traveling slower than other traffic.

The second part applies no matter how fast you are going. Notice that the law only says that traffic moving "more slowly" than other vehicles; there is no exception given for vehicles traveling the posted speed limit. If you're going the speed limit in the left lane and someone behind you wants to go faster, move over! You don't have any right to enforce the law (that's called vigilantism), and you're actually violating the law by not moving over. You never know-- that person may have a bona fide emergency (okay, probably not, but you never know.)

On the other hand, if you're the one behind the slower driver, have a little patience and give them a few seconds to realize you're there and to move over before you zip around them. I can't count the number of times I've seen someone in the left lane who wanted to move over but got trapped there because everyone immediately passed them on the right. Plus, the weaving of drivers who are constantly passing other vehicles causes hazards and the turbulence caused by those frequent lane changes is a frequent cause of so-called "phantom" traffic jams.

This is probably one of the least-known laws. When someone from the left lane and someone from the right lane both try to move into the same space in the center lane at the same time, who should yield the the right-of-way? In Texas, the law is that the person changing lanes from right to left must yield to someone trying to enter the same lane from the left. The reason why the left lane driver has priority is because the they may be moving over to allow another vehicle to pass, because they're getting ready to exit, or because they have an emergency and need to move to the shoulder.

One lane at a time
While there is no law specifically prohibiting multiple lane changes, §545.060 requires motorists to "drive as nearly as practical entirely within a single lane". Therefore, if you move across multiple lanes, you could be found to be in violation of this law, not to mention that doing so is fraught with danger. Therefore, you should only change one lane at a time. If you need to get across several lanes, move over one lane, establish yourself in that lane for a few seconds, then move over to the next lane. And don't forget your turn signal each time as required by §545.104!
 

What is the speed limit on the curve marked by the sign at the left? Most people would say 25 mph, but the answer is that we don't have enough information to know what the speed limit is here. The "25 mph" sign here is a speed advisory sign, not a speed limit sign. Speed advisory signs indicate the recommended speed for a particular hazard, but they are not a legal speed limit. Enforceable speed limits are marked by the familiar black and white SPEED LIMIT signs. So, the speed limit for this curve would be whatever the last black and white speed limit sign indicated (or the default speed limit for that type of roadway in the absence of a speed limit sign.)

Despite that, it is a good idea to travel at or near the speed indicated on these signs-- you could still be cited for unsafe speed if you're traveling appreciably faster than what is posted, especially if you crash.

Advisory signs in work zones
Thumbing its nose at national signage standards, Texas has an unusual law (

Additional information
A study by the Federal Highway Administration back in the '90s determined that the formula used to calculate the advisory speeds on curves, which was developed back in the 1930s, was significantly outdated and was producing advisory speeds that were 10-15 mph below what modern vehicles can safely and comfortably handle. New methods and procedures for improving the setting of advisory speeds have been developed and many states are now updating advisory speed signs. If you are used to ignoring advisory speeds because they seemed too low, you'll need to start paying more attention to them.