Home | About me | Contact | What's new | Privacy | Search
 

San Antonio
Freeway system
Other roads
History
FAQs

Search this site
 
This site is not affiliated with any official agency.


ADVERTISEMENT

San Antonio Area Roads & Freeways
Frequently Asked Questions

This page last updated February 19, 2020

ADVERTISEMENT

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

TransGuide

HOV lanes

Loop 1604

Other
  • Why don't they plan and build new roads before new developments are built?
    This is answered in detail on the Why don't developers have to expand the roads first? 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 complicated. 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.




If you found this site informative, please consider making a small donation to help support it. Thanks!

This page and all its contents are Copyright 2022 by Brian Purcell

NOTICE
The information provided on this website is provided on an "as-is" basis without warranties of any kind either express or implied.  The author and his agents make no warranties or representations of any kind concerning any information contained in this website.  This website is provided only as general information.  The author expressly disclaims all liability with respect to actions taken or not taken based upon the information contained herein or with respect to any errors or omissions in such information.  All opinions expressed are strictly those of the author.  This site is not affiliated in any way with any official agency.