Planners know Phoenix's most dangerous intersections. Here's how they're making them safer

By Mark Brodie

Published: Thursday, January 11, 2024 - 11:33am

Updated: Thursday, January 11, 2024 - 12:55pm

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The intersection of 19th and Peoria avenues in Phoenix is considered of the most dangerous in the metro area.

The Maricopa Association of Governments, or MAG, recently compiled its annual list of the intersections most at risk for crashes — it’s been doing this since 2010. The regional planning agency analyzed more than 22,000 intersections across the region — the first step of several. MAG will issue recommendations to local agencies by next summer.

Many of the intersections with the most crashes were in the West Valley — including 99th Avenue and Lower Buckeye Road, 75th Avenue and McDowell Road, and 99th Avenue and McDowell. But, Margaret Herrera says since this list is a high-level one, it doesn’t really say much to her that intersections in one part of the Valley have more crashes than in other areas.

Herrera is MAG’s transportation safety and operations program manager..

Full interview

What kinds of things do you need to look at to determine if there’s anything the intersections with a lot of crashes have in common, or if there’s something unique about them?

MARGARET HERRERA: Sure. So a lot of times what we'll do is take a look at, for instance, if there's an area with heavy truck traffic, right? Or if you have an area that's high commercial, other areas that are a mixed use of commercial, both single family and multifamily residential, along with services and community centers like parks or churches, right.

So, there's several things that we look at that we, we do see some trends, especially in the areas that I just described to you with those mixed uses, where we might see a lot of pedestrian and bicycle crashes. You might also see a trend in left-turn crashes, and those are in some areas where you have opposing left-turn lanes that are lined up directly in front of each other and you can't see around, you know, the through traffic to, to accurately judge a gap. So you might see some trends, as far as that's concerned.

Would I be right to assume that the speed in, in these areas and maybe even the types of vehicles you mentioned, like, are they residential, are they, you know, industrial, are they commercial, like that kind of affects what kinds of vehicles are, are on the roads there, too, right?

HERRERA: Absolutely. So you have an area that's high industrial, you're gonna have a lot of freight, right? You're gonna have a lot of truck traffic. So, so that is, that is a good point that you make.

So you mentioned that this is something that you have done every year for a while now. Do you see the same intersections popping up year after year?

HERRERA: That's a really good question we have seen over the years some movement from, you know, some corridors will be on the list for several years and then, and then they'll reduce and then other corridors will, will prop up. We, we take a look at the previous year's list to see what that movement is. We've had some intersections that were, you know, in the top five, go down to 96, right? And, you know, we have several intersections that, you know, may stay in the top 100 but they might move, they might move up, they might move down.

Yeah. Well, so is there anything that you can learn, for example, from a, you know, an intersection that might have been in the top 10 or the top 20 that has gone down significantly? Can you take anything that you have learned and done in that intersection and apply it to another one that maybe has cropped up to the top, you know, 10 or 15?

HERRERA: Yeah. And that's another really good question. Those are things that we always look out for as well, to see, you know, if, if something's performing well, how can we duplicate that elsewhere, right? We did have an intersection that was,, ranked in the top five, about six years ago, I want to say. And they, the local agency had done some, had applied for funding at MAG, through their, through our roadway safety program and did some left-turn improvements and we did see that one drop out of the top 100 this year. So looking at those specific improvements that they made, we can definitely screen the rest of the intersections in the region to see if there's places where we can duplicate that. So that that again, is, is something that we continually do.

Right. Well, I, I assume that there are only so many things that you can do, right? Like you have a a toolbox of options, given all the factors you mentioned earlier about, you know, some of the the attributes of a particular intersection. But I would think that there are some things that like maybe aren't really doable in terms of changing infrastructure or things like that. So is it, like how broad or narrow is the universe of, of potential fixes that you can apply to an intersection?

HERRERA: Right. And, and, and again, I can tell you that we try to broaden our tool kit as much as possible. Think of it more in terms of not how many tools, but what tools work the best, right? We try to focus on the things that will provide or have, you know, documented with the highest potential for improved safety.

But I can tell you that we, we do provide recommendations to the local agencies that go from anywhere from education programs for the area that they might want to implement, you know, increased engagement by police officers, infrastructure. You know, the things that are really hard to do are, you know, as it relates to speed. But we, we try to make sure that the recommendations that we put in there are going to be the ones that will give them the biggest bang for their buck, regardless really of the cost. You know, one of the things that, you know, we need to kind of wrap our minds around is that to make some real safety improvements, you know, we're going to have to spend some money to do it.

Well, so understanding that, you know, each intersection is to an extent unique over the years. Are there particular recommendations or particular solutions that you have found generally are fairly successful?

HERRERA: Yes. And I spoke about this a little bit earlier but the, you know, making the improvements to the left-turn pockets, where you're giving the drivers more a better view around the opposing left turn to be able to judge that gap. Those have been very successful. The flashing yellow arrows have been successful. You know, things like we talked about the range earlier of different, improvements that you can make. You probably have seen some traffic signals that have a yellow retro reflective border on them, that can really improve the sight of the, you know, red, yellow, green if the sun is at your back, right. So if you're getting some glare off of the sun, those go a long way in improving the site of the actual traffic signal itself.

So there, there's a lot of things that have been successful and they range from some of the larger, infrastructure improvements all the way down to even signal timing, right. We might make recommendations to extend the green time or provide pedestrian priority, right, in areas where we have a lot of like light rail, right, where we have a lot of pedestrian crossings. So the things like that have been successful.