red light cameras

The City of Sacramento has 11 red light camera locations: Red Light Running Program. Of these, some are at high-injury intersections, but most are not. These locations are cross-referenced with high injury intersections shown in the post Sac Vision Zero new intersections map.

LocationTop allTop pedTop bike
Mack Rd & La Mancha Way/Valley Hi Drnonono
El Camino Ave & Evergreen Stnonono
Howe Ave & Fair Oaks Blvdnonono
Mack Rd & Center Parkwaynonono
Exposition Blvd & Ethan Waynonono
Broadway & 21st Stnonono
Folsom Blvd & Howe Ave/Power Inn Rdnonono
Arden Way & Challenge Waynonono
5th St & I Stnonono
16th St & W Stnonono
Alhambra Blvd & J Stnonono

My first thought is that the city was putting these cameras in the wrong location. But then I thought, what if the presence of red light cameras is making these locations safer and therefore dropping them out of the highest injury intersection list. I don’t have the information to answer that question, which would take analysis of crashes at the intersections, and before/after data.

What I do know is that many more red light cameras are needed to counteract the pandemic of red light running: pandemic of red light running. I spend time around the edges of Fremont Park, close to where I live, which includes the intersection of arterial streets P, Q, 15th, and 16th, and one of the things I do is watch traffic in the intersections. It has now become rare for a signal cycle for 16th St northbound at P St to not see an incidence of red light running. The other intersections are not quite as bad, but the pattern is there. And this is happening everywhere in Sacramento that I go; these are not likely to even be the worst intersections.

I believe that most of the red light running is by egregious violators, people who routinely and continuously violate traffic law for their own convenience or thrill seeking. This is true of most traffic violations, but red light running is the one most likely to result in fatality and serious injury, for people in all modes of travel. So having a more widespread set of red light cameras would serve to catch these red light violators. Of course the follow-up is necessary, to revoke the licenses and confiscate the vehicles of these repeat offenders. The longer the city looks the other way on this issue, the more people will come to see it as normal behavior, and the less safe our streets will be.

The standard response by cars-first entitled drivers is that tickets are just a money-making scheme by the government. The purpose of red light cameras is to make streets safer, and if that results in some income, so be it. I’m more than happy to have these sociopathic drivers hit in the pocketbook, and the money can be used to make our streets safer, such as by installing more red light cameras. Red light tickets, with photos, are part of the documentation needed to revoke licenses and confiscate vehicles.

Sac Vision Zero new intersections map

Thinking about the intersections maps and what they show (Sac Vision Zero top intersections all modes, Sac Vision Zero top ped intersections, Sac Vision Zero Top 5 Corridors and top intersections), I thought it might be interesting to present the data in a different way. The two maps below show all of the top intersections identified in the all-modes, pedestrian, and bicycle data. They are divided into a north section and a south section so that the intersections and their labels are visible. The maps are available as pdfs (north, south).

legend for intersections on maps below
Sacramento top collision intersections, north section
Sacramento top collision intersections, south section

The intersection data is in the table below.

What’s next? I’ll take a closer look at some of these intersections. For people who follow traffic engineering, it will probably be immediately obvious why these intersections are dangerous. A detailed analysis requires looking at each collision record individually, which I don’t have time to do. The city did make use of incident reports, which contain more information than the data in SWITRS, in developing the Vision Zero Plan.

Sac Vision Zero Top 5 Corridors and top intersections

As promised in my previous post, Sac Vision Zero flaws, here is a limited analysis of high injury network intersections in Sacramento. I used bicycle crashes for 2014 through 2018 from the SWITRS crash database, and matched these to intersections of arterials and collectors in the city. It is known that most crashes occur at or near intersections, not in between. Of the 1112 crashes in this time period, 763 occurred at intersections, or 69% (for all crash types, the city said it is 78%). I selected eight intersections to highlight, which had 4, 5, or 7 crashes at the intersection or within 120 feet of the intersection, meaning on the approach or departure from the intersection. The other 590 intersections had 3, 2, 1, or no crashes. I did not analyze the crashes for fatality or serious injury, but that would be a useful.

The map below shows the Sacramento Vision Zero Top 5 Corridors, in red, and the top eight crash intersections with a bicycle symbol. The number to the right is crashes, and the location is labeled with cross streets. This is also available as a pdf.

Of the eight intersections, one is part of the Florin corridor, at 24th Street and Florin Road. The other seven are not.

I ask that the city revise its Vision Zero program to include high injury intersections. The number might be as many as 10, and selection should include the same equity criteria used to select the corridors. That means that the three central city locations might not be selected, or might be lower on the priority list, and that is good. The challenge of the Stockton Blvd & Fruitridge Road intersection is that it is on the city/county boundary, so complete treatment of the intersection would require some cooperation with the county. But with seven bicycle crashes in the time period, it is a very important intersection.

A strong advantage to giving high injury intersections recognition and attention is that they could receive near-term safety improvements that require only reallocation of roadway width and new paint. Full safety improvements probably would require redesign of the intersection.

Again, I fully support the city’s Vision Zero efforts, and want to see them be the best they can be. That means including high injury intersections.

Addition 2021-03-02: Someone asked how the bicycle collision locations relate to disadvantaged communities. Below, a map with CalEnviroScreen 3 2018-06 (CES) layer, with red end being higher pollution, green being lower, and weighted with income. CES is not the only measure of disadvantage, but it is one commonly used.