Measure 2022: interchanges galore!

Note: I had said I was pausing on the proposed transportation sales tax Measure 2022, but I’d forgotten to write about interchanges.

The proposed transportation sales tax measure Exhibit A: Transportation Expenditure Plan includes 31 instances of ‘interchange’. If you aren’t familiar with the term, it means the intersection of freeways and expressways with other sorts of roadway, or with other freeways and expressways. Two examples, one of a freeway interchange, and one of a freeway and arterial interchange:

Hwy 50 & Business 80 & Hwy 99 interchange
Hwy 5 & Cosumnes River Blvd interchange

Interchanges are very popular in the proposal.

location#
Citrus Heights2
Elk Grove2
Folsom5
Galt1
Rancho Cordova4
City of Sacramento5
County of Sacramento2
Highway Congestion Improvements4
interchanges in the TEP

Interchanges are very expensive. Miles of sidewalk or bike lanes could be constructed for the cost of one single interchange. Or new buses or bus-only lanes, or new light rail cars, or a bike-share program. Interchanges are far more expensive than the straight sections of freeways. Interchanges take a good deal of land, removing it from productive use and leaving wastelands in between that are not accessible and not usable for anything else. Interchanges are complex for drivers, so have many far more crashes than the straight sections.

Probably most important, freeway on-ramps and off-ramps create the most hostile and dangerous points for people walking and bicycling. Though interchanges can be build with right angle turns to enter from and exit to surface streets, and can be signalized so as to allow safe passage by walkers and bicyclist, they were never built that way in the past, and are only sometimes built that way now. Instead, there are swooping on-ramps that encourage drivers to reach freeway speeds while still on the surface street and ramp, and off-ramps that encourage drivers to maintain freeway speeds coming off the ramp and continuing on the surface streets. If you don’t believe this, please watch a freeway off-ramp for a while, for example, if you live in central city Sacramento, I-5 to P Street off-ramp, or I Street to I-5 on-ramp. You will see people going 55 mph or more on the surface street, slow to decelerate and quick to accelerate. Freeway on-ramps and off-ramps kill hundreds of walkers and bicyclist a year.

Our freeway system was essentially complete years ago, with the 1972 completion of the I-80 (then I-880) northern bypass. Freeways provide quick travel from point A to point B. As earlier explained in the streets – stroads – roads post, roads that imitate railroads, for quick travel between productive places, are a good thing. The original idea of Interstate highways was, for the most part, a good idea. Of course then they were driven through the heart of cities, including Sacramento, lost most of their value as travel routes, and destroyed the value of the cities they went through.

So why, now, do we need more interchanges, more points of access to and from freeways? The answer is almost entirely greenfield development, and the promotion of car trips for commuters from those greenfield developments. Interstate 5 and Interstate 80 could easily handle all the freight and long distance travel demands with two lanes in each direction. So what are all the other lanes for? Commuters. And what are all the new interchanges for? Commuters. Note that in this use of ‘commuter’, I’m including not just home to work trips, but all the other trips that are induced by having more lanes and more interchanges. Job-related trips are now only about 20% of all trips, even before the pandemic. For the existing interchanges proposed to be improved, the reason again is primarily the induced travel through greenfield development. If there weren’t new greenfield development, there wouldn’t be increased traffic.

Each interchange reduces the safety and speed of the freeway. Each interchange encourages motor vehicle trips that would otherwise not occur, by allowing people to travel longer distances more quickly, therefore considering living and working and shopping and recreating in places they would not have otherwise considered. Of course the convenience is illusory. It makes sense right after the new lanes and interchanges are added, but the law of induced travel quickly fills those lanes and those interchanges, generating calls for more lanes and ‘improved’ interchanges. Which induces more travel, which…, well, you get the idea.

If you haven’t, please walk or bike to any of the freeway overpasses in the Sacramento region, and spend some time observing the traffic below. You will see freight traffic, trucks trying to get through the area on their way somewhere else, stuck behind commuter traffic, crawling along. You will see most vehicles carrying a single person, what are called single-occupant vehicles (SOVs), but taking up the space that could be serving multiple individuals. Though there are only a few freeways where buses also run (I-80 towards Davis and I-5 towards the airport), you will see those multi-passenger vehicles stuck in traffic with SOVs.

The second Google map above, showing the new interchange at I-5 and Cosumnes River Blvd, is instructive. Why is the interchange here? To serve the Delta Shores development, which is currently just a suburban big box store shopping area, though it was intended to and may eventually serve new housing. This area was greenfield before, agricultural farming or ranching. The purpose of the interchange is not to serve existing drivers or residents or city, but to create new drivers, new customers in this case. It is true that a portion of the cost of the interchange was paid for by the developers, but there was still a huge cost to us, the taxpayers.

If you want a lot of new and improved interchanges, which induce more motor vehicle trips, pave over greenfield areas, and create serious hazards for walkers and bicyclists, then the proposed measure may be to your liking. If not, then I hope you see it as the wrong road to travel.

Search for category Measure 2022 to see posts as they are added.

I-5/Richards Interchange

The City of Sacramento is soliciting comments on its Interstate 5 / Richards Boulevard Interchange Project. Please take a look and comment.

My comments are summarized as:

  • 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.