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.
And now for the third analysis of high injury network intersections and the relationship to the Sacramento Vision Zero Top 5 Corridors. The dataset this time is all killed or severe injury collisions in Sacramento, for all modes of travel, for the period 2009-2017. Of the 1641 collisions in the city, 322 (20%) were at intersections defined by the intersection of arterial and/or collector streets. There is also a pdf map available.
Of the eleven intersections with four or five collisions, three are on the Top 5 Corridors:
Stockton Blvd & Broadway, 4 (on Stockton-Broadway corridor)
Stockton Blvd & Lemon Hill Ave, 4 (on the Stockton South corridor)
Stockton Blvd & 47th Ave & Elder Creek Rd, 4 (on the Stockton South corridor)
and eight are not:
Watt Ave & Auburn Blvd, 5
Del Paso Blvd & Evergreen St & Lampasas Ave, 5
Julliard Dr & Kiefer Blvd & Folsom Blvd, 5
Power Inn Rd & Fruitridge Rd, 4
Freeport Blvd & Florin Rd, 4
Center Pkwy & Cosumnes River Blvd, 4 (not on map)
Bruceville Rd & Cosumnes River Blvd, 4 (not on map)
Franklin Blvd & Mack Rd, 4 (not on map)
The three last intersections are not on the map because I wanted to maintain the same scale as used for the previous maps, but they would be off the south edge of the map. Note that the number of collisions at these intersections is not directly comparable to the bicycle collisions map I created because I used a different dataset, degree of injury and span of years. I may go back and update the bicycle map to be consistent, but it is probably more worthwhile to look at some of these intersections in more detail.
The safety justification doesn’t hold water. The interchange itself has no fatal collisions and no severe injuries during the period of time analyzed (safety starts at about 9:56 in the video). The severe injury collisions are all outside the project area. The city is definitely trying to gaslight people on the safety issue. If the city were actually concerned about safety, they would be doing projects at the severe injury locations. But they are not. In fact, unnecessary projects like this one gobble up the funds that could be used to solve real safety issues. It is worth pointing out that this area is not a high priority in the city’s Vision Zero program. There are many, many areas in the city with far higher collision rates.
The information on bicycle and pedestrian improvements is very fuzzy. Nothing is indicated that to me makes is seem safer for either. More traffic means less safety, unless the safety improvements are substantial, and I just do not see that here. See DDI comment below.
The project points out rightly there there will be increased demand for travel as a result of residential, commercial, and public development in the Railyards and River District areas. But it makes no mention of other ways of solving the issue. Demand management? Never heard of it. The project simply accepts that traffic congestion will get worse if no infrastructure is built, so infrastructure must be built. Of course the EIR has to consider the no-build alternative to be legal, but the city is certainly not presenting that option to the public.
The project uses traffic delay through the interchange (on the interstate) to justify the project. The current traffic delay is due to the fact that commuter traffic has been encouraged by the provision of additional capacity on Interstate 5 to the south of the city, and on Interstate 80 east and west of the city. Of course things will get worse at this location, as more people commute and travel on this increased capacity. This is called induced travel, and is to be expected. Induced travel is increased by capacity expansion projects.
The city wants to spend $46 to $100 million of your tax money to ‘solve’ this problem. If we let them do that, they will be back in a few years with another project to ‘solve’ the problem at some other nearby pinch point, and the new project will be even more expensive because they have induced more travel by ‘solving’ the perceived congestion problem here.
It is time for us to demand that highways engineers be cut off from building new capacity. They see the taxpayer pockets as their piggy bank. Fix what we have, and invest the remaining transportation funds in supporting walking, bicycling, and transit.
The projects proposes making the interchange into a diverging diamond interchange (DDI), where the travel lanes switch sides under the freeway so as to reduce the number of intersections, and to ease common vehicle movements. Some people hate DDIs. Traffic and highway engineers love them. I’m pretty indifferent. I have spent a lot of time observing DDIs, before and after. They do offer some improvement in traffic flow, and they do offer minor improvement in safety for drivers. They are not any better or worse for bicyclist and pedestrian comfort and safety, IF they are designed properly (I’ve seen some very poor installations, some of which won awards from AASHTO, the highway lobby entity, that never saw an expensive project it did not love). It does take a period of a year or two for people to adjust to the different feeling of a DDI, but that is not necessarily bad. So my opposition to this project is not due to the DDI, but other issues. Others may feel differently.