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San Antonio Area Roads & Freeways
Frequently Asked Questions

This page last updated February 19, 2020


Below are some of the most common questions or complaints I get about San Antonio roads and freeways.

Specific projects
The following projects have FAQ sections on their own pages:

Road construction generally


HOV lanes

Loop 1604

  • Why don't they plan and build new roads before new developments are built?
    That is a lot easier said than done. Transportation agencies don't know what's coming until a developer submits their plans, and even then, there's no guarantee the development will be built. When a development is submitted, the developer is usually required to conduct a traffic impact analysis and then mitigate the projected impacts, either by constructing improvements or paying an impact fee. Generally, the impacts from individual developments will be in the immediate area, and mitigating improvements will usually consist of turn lanes, intersection improvements, and signals. The issue is that there is really no way of forecasting what the impacts will be to roads further afield. For example, how many people from a new development will head north on the nearest freeway vs. those that will head south? There's no way to know until that traffic materializes. Furthermore, the impact from a single development further afield is generally trivial, so even if it could be accurately determined, it would not be enough to require mitigation. Instead, it's the cumulative impact from multiple developments over time that cause those issues, and so it's impossible to retroactively assess specific impacts to individual developments.

    Even if they had a crystal ball, it still takes several years before road projects can come to fruition. First, there's the design and engineering, then environmental clearances, obtaining funding, then right-of-way acquisition and utility relocation. All of that has to happen before the actual project to build or widen a road can start, so it's generally a minimum of five years before a major road project can break ground. In the meantime, they can't legally stop the developer from continuing with their project, so those new developments are often well underway or even complete before road projects can get underway. See also the last question on the 
    road construction FAQ page.

  • So why not, then, build or widen roads ahead of the development?
    A good idea, except that with all of the existing needs that struggle to get funded, there's certainly not money just lying around to build new roads out in the middle of nowhere based on hypotheticals. And if they did and the growth didn't come for some reason, that would result in a lot of wasted money. For example, the Poteet-Jourdanton Freeway on the South Side was 
    overbuilt when it was initially constructed back in the '50s because it was believed that San Antonio would grow south. It didn't, and,as a result, it's much more road (which costs more to mainain) than is needed for the level of traffic it carries even today. See also the last question on the road construction FAQ page.

  • What was the first freeway built in San Antonio?
    The section of the lower level of I-10 (then just US 87) between Woodlawn and Culebra. It quietly opened in July 1949. (See the San Antonio Freeways History page for a complete history of the freeway system.)

  • What's the deal with SH 211? It's a road to nowhere and a waste of money.
    The first section of SH 211 opened in 1990 to provide access to the now-defunct Texas Research Park. Because of its location, TxDOT planners knew that it would make an ideal location for a far west Bexar County beltline, an idea that had been around for decades. Like many projects, construction on SH 211 was split into several segments due to funding constraints. Unfortunately, due to issues with right-of-way acquisition, the missing middle segment has languished unfunded for years. However, in 2009, Bexar County agreed to build the missing segment and get reimbursed by the state over several years. See the SH 211 page for additional information.

  • Why doesn't TxDOT upgrade Bandera Rd. through Leon Valley?
    Since the late '80s, various upgrades to Bandera Rd. in that area have been proposed, including adding flyovers at major intersections and an elevated tollway, but the City of Leon Valley vetoed all of the plans on the belief that such upgrades would hurt local businesses by speeding traffic through the city (a serious fallacy in my opinion; congestion hurts businesses more than improved access would.) Fortunately, fresh leadership in recent years has resulted in a change to Leon Valley's official position and will hopefully result in much-needed improvements. See the Bandera Road proposals page for more details on current planning for that corridor.

  • Why aren't traffic signals in San Antonio synchronized?
    Actually, most of them are. See the City of San Antonio's traffic signal management page for details and see this video to see it in action. That said, if you're on a road and it doesn't seem like the signals are synchronized, here are some possible reasons why:
    • You're traveling faster than the speed limit. Signals are synchronized for to allow a group of cars (a "platoon") moving at the speed limit of the roadway. If you're speeding and get out ahead of the platoon, you could arrive at the next signal when it's still red.
    • You're traveling significantly slower than the speed limit (either because you're lollygagging or due to traffic.) If you fall behind the platoon, you could arrive at the next signal as it turns yellow or red.
    • The road you're on intersects with another road where signals are synchronized. If the synchronization on one roadway conflicts with that on the other, then one will have to prevail over the other.
    • You're headed in the opposite direction of the timing. Sometimes, signals on a roadway are only timed for traffic headed in one direction (i.e. the direction with the heaviest flow of traffic.)
    • The traffic volumes on the road you're on exceed the capacity of the traffic signals. For a more in-depth explanation, see the related question in the FAQ on the Bandera Road page.
  • Congestion in San Antonio could be solved by just timing the signals better.
    This is a common assertion and can be true in some specific cases. But most of the time, it's way more compllicated. At most busy intersections, there has to be sufficient green time for eight different movements on every cycle, so the signals can only be optimized so much before the laws of physics win. For example, the green time on road A could be extended to help clear out the backups that occur there, but that means the light will stay red longer for road B, which then increases the congestion there. If the green time for road B is then increased to ease those backups, that means the light will now stay red longer for road A and you're right back where you started. So as you can see, it's really not as easy as it sounds. Then scale that zero-sum complexity over an entire corridor and you see just how naive "just time the lights better" really is.

  • If I'm at a red light and nobody is coming on the intersecting road, why doesn't the light turn green for me right away?
    There are several reasons why this can happen:
    • If the intersecting road has synchronized traffic signals, then your signal will have to wait for scheduled gaps in that "green wave" before it can change. When signals are synchronized, the green times on the major road are fixed by design and typically can't be preempted except for emergency vehicles.
    • The minimum green time on the intersecting roadway hasn't yet expired. Whenever a signal turns green, there is a set minimum amount of time it will stay green. If a pedestrian signal has been activated, the minimum green time will usually be longer.

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