Here are some comments from Road Warrior readers:

Why not better traffic lights?

About 6 years ago, I moved from a town of about half a million people to Santa Rosa, but I still travel around the country quite a bit for work. I’ve noticed that many cities only use protected left-turn lights when there is little to no visibility of oncoming traffic to make a safe left turn, theoretically, without assistance (due to blockage or curvature in the road). Sonoma County seems to use many more protected left-turn lights even at small intersections, subsequently restricting traffic flow.  Interestingly, most of these protected left-turn intersections aren’t large enough to have protected right turns or permitted “U” turns with traffic entering the same direction of traffic flow, as the driver in question turning left.  Clearly I’m failing to understand the cause or source of these types of protected left turns.

As a matter of fact, I have a little theory (wouldn’t you know) on how this negatively affects traffic patterns of drivers.  Since there are so many protected left-turn lights, drivers aren’t as used to yielding to oncoming traffic at solid green left-turn lights.  Last year at Farmers and Montgomery, I witnessed an accident at a good-sized intersection using (the somewhat rare, according to me) unprotected left-turn light (solid green, with a “Yield to oncoming traffic” sign posted next to the light).  The driver in front of me was turning from westbound Montgomery to southbound Farmers and thought he had the right of way, driving head on into an oncoming car heading eastbound on Montgomery.

In Sonoma County, we have lots traffic lights like the example below:


I’m in favor of more traffic lights (used more in larger cities) as seen in this example:


In other cities they have more lights like Example #2 (helping traffic throughput) as opposed to more lights like Example #1 (restricting throughput).  We’re restricting throughput in this county and increasing people’s likely hood to run a red light — because they’re penalized with additional wait time — if they miss the green arrow.


Safer intersections in Arizona

In Tucson and Phoenix, at intersections with traffic lights, the left-turn signals turn green to indicate a left turn is OK after the main traffic lights have turned red.  The through traffic is stopped at the red light while traffic wanting to turn left does so.

In Santa Rosa, the left-turn signals turn green first or turn on at the same time as straight through traffic lanes.

Often, what I see, is that more drivers run the red left-turn arrow driving through the intersection well after the green left-turn arrow changes. Whereas in Arizona, the green left -turn arrow is activated after the main traffic light turns red.  Traffic comes to a stop and the left-turn lane is free to turn left.

It is my opinion that Arizona has safer intersections.  Ana


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  1. Robert B. Tanner

    The whole issue of traffic operations with the frankly outdated “Wait for arrow” protected left-turn has been a sore spot for me for the last 25 years. This signal results in unacceptable wait times, increased red-light running, delays to bus service, increased air pollution from too many idling vehicles, discouragement to biking and walking and a host of other issues.

    The poster “MC” recognizes the problem, however there are two NEW ‘Protected-Permitted’ left-turn signals now allowed for use in the new 2012 California edition of the Manual on Uniform Traffic Control Devices. (MUTCD)

    One has an extra yellow arrow on the left-turn faces that flashes when unprotected left turns are allowed. The other simply flashes the existing red arrow when an unprotected left turn is allowed. (You treat this like a stop sign.)

    These new signals are far safer than the older ‘Five-light’ signal “MC” showed, as the indications are easier for people to understand. There have been problems with drivers treating the old solid green ball as clear and safe and not paying attention to the sign, ‘Left Turn YIELD on Green’. They then turn left, right into opposing traffic, causing a horrendous collision. This is why Petaluma had to scrap their Protected-Permitted system last year.

    I agree with “MC” that something needs to be done about the overuse of protected-only turn arrows but i strongly support the Flashing RED Arrow light as a replacement for the present system.

    Also, the new signals allow the red arrow to stay solid if a pedestrian is in the crosswalk with a ‘walk’ signal that is in the path of a left turner.

    January 12th, 2013 3:53 am

  2. Naomi Williams

    I agree 100%. It is so frustrating to sit there waiting for that green arrow when there’s not a single car coming from the other side of the intersection. I think this would do a lot to safely clear up congestion.

    January 12th, 2013 5:44 am

  3. Eric Lindenbusch

    I couldn’t agree more with this letter from Ana! One blatant example of what she’s referring to is the red left turn arrow on eastbound Bennett Valley Road turning left onto Brigham Ave. I’ve never seen westbound oncoming traffic to a degree that would warrant a red left turn arrow. In some places in Oregon and Idaho, there are flashing yellow left turn arrows that mean the same thing as left turn yield on green which I think works wonderfully. I would really hope that Santa Rosa and other Sonoma County towns would review each traffic light intersection to see which ones could have their red left turn arrows replaced with left turn yield on green (or better yet, the flashing yellow left turn arrows). One more thing: After, say, 11 at night, have flashing yellow lights along main streets with little cross traffic at that time, with flashing red lights for the residential streets that intersect with these main streets. This would do WONDERS for improving traffic flow late at night. Brookwood Ave. between College Ave. and Second St. is a perfect example. How infuriating it is to sit forever at a red light when there is no cross traffic to trip the magnetic sensor and make the light change.

    January 12th, 2013 10:38 am

  4. Alan Stevens

    All these different signal lights, so confusing. Why is everyone in such a big hurry? Let’s get rid of the automobile and all ride bicycles.

    January 13th, 2013 8:23 am

  5. DZerach

    As a past resident of Tucson, a large city without any freeways whatsoever going through town, may I share that the LEADING left-turn green arrow light does not necessarily increase safety. Oncoming, opposing traffic can still easily collide with the driver who chooses to race to beat the light because he doesn’t want to sit there for another round. The only thing that helped the safety issue were cameras at intersections to ticket red light runners (enforcement). The fact will anywhere and always remain that making a left hand turn is the most dangerous move available in traffic, however it is engineered. There are three prongs to traffic problems: engineering; education; and enforcement. The amount of traffic engineering in Santa Rosa is indeed overkill. Yet presumably reflect thoughtful, well-considered decisions of past engineers? Do we know why all of these left-turn restrictions were installed in the first place? A basic driver’s knowledge of “left-turn on green always yields to oncoming traffic” should suffice? Someone who doesn’t even know to yield on green when making a left hand turn has missed out or forgotten even the kindergarten level of driver education.

    January 13th, 2013 10:52 am

  6. Andrew

    One issue that is often overlooked about left turn arrows is the fact that quite often at intersections with the arrows, is that when no vehicles are in this specific lane, nor have tripped the sensor(s) to turn left, the arrows are still operating, and thusly halt traffic from continuing straight and causing traffic backups and delays.

    I live in Petaluma, and most if not all of the major, and some minor intersections are like this. It makes absolutely no sense to have these left turn arrows operate like this if there are no vehicles using that lane. I have spoken with traffic control, and even the Petaluma PD( of which one of these intersections is right next to the station ), and they give no explanation other than to say, “this is what the City, County, and State require we do.”

    January 13th, 2013 12:14 pm

  7. Dar

    Another person voting for less restrictive left turns in/around Sonoma County. This has been a great frustration of mine since moving up here from Oakland in 2007.

    January 13th, 2013 3:21 pm

  8. Adam Carolla

    I have be ranting about this issue for over a decade. I implore all drives to ingnore the red turn arrows and procede through the intersection when it is safe to do so.

    January 14th, 2013 10:32 am

  9. stephen

    I”ve been saying, since I moved to the north bay 4 years ago, that the roads up here are the worst designed roads I’ve ever come across.

    They are in massive need of updating.

    January 15th, 2013 5:07 pm

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