Tag: slip lanes

What’s next: squeeze roadways

Dan Allison1 Comment

Part three of what’s next, part two being What’s Next: parking, and part one being What’s next: freeways. Radical ideas for what to do now that the road safety and transit initiative SaferSacStreets did not make the November ballot.

Without additional funding, the city will continue to seek grants for infrastructure projects, and will continue to make some traffic calming changes such as temporary curb extensions, both of which are good. But the huge number of poorly designed roadways, and in particular unsafe intersections, means that progress would be measured in decades if not longer. The capacity of arterial and collector streets must be reduced, but with actions that don’t require much money, since there won’t be much money.

Immediately close all slip lanes: Slip lanes allow high speed turns with drivers looking only left for other vehicles, never right for people walking. Even when stop signs are present, drivers make high speed turns. These are a clear and present danger to people walking, and should immediately be closed, with vertical delineators, or concrete barriers. This would also have the effect of reducing roadway capacity.

Close all dedicated right turn lanes: Similar to slip lanes, dedicated right turn lanes increase roadway capacity and decrease safety. Again, drivers look left for other motor vehicles and not right for walkers. These lanes also lengthen crossing distance for walkers at the intersection. Closure can be with vertical delineators, or concrete barriers.

Close all dedicated left turn lanes beyond one: Multiple left turn lanes are a hazard to drivers, increase the capacity of a roadway in such as way as to encourage drivers to consider the roadway a highway, and lengthen crossing distances for walkers. Drivers are paying attention to the vehicle beside them and not to what is ahead of them. Left turn lanes are a positive for traffic flow, but one does it. Closure can be with vertical delineators, or concrete barriers.

Close unnecessary center turn lanes: Center turn lanes may be appropriate where there is a density of driveways and therefore turning movements, and only one general purpose lane per direction. Otherwise, all traffic must wait behind turners, and people turning onto the roadway create conflicts with through traffic. Center turn lanes are a hazard – a common name for them is ‘suicide lanes’ – but they can be useful in some areas. However, they are unnecessary where there are two or more lanes in a direction, increasing capacity but with a significant negative safety effect. Closure can be with vertical delineators, or concrete barriers.

Remove all lanes over two per direction: This is probably the most expensive suggestion, since there are miles of three lane arterials in Sacramento, and far more outside the city. Transportation advocates refer to these roadways as ‘traffic sewers’, intended to flush motor vehicles in and out of the city during commute times. They feel like highways, and they are used like highways, drivers traveling at high speeds and not expecting any conflicts. Intersections on these roadways have much higher crash rates than other locations. Perhaps we could start with roadways with a demonstrated higher crash rate.

Reducing roadway capacity is directly contrary to the design of roadways over the last 70 years, which is to speed and ease the flow of motor vehicles. It is also contrary to the desires of most traffic engineers. But it is exactly what we need to do, to discourage motor vehicle use, to reduce environmental impacts, and to make our roadways safer places for everyone. And in particular, to start the process of making people walking and bicycling to once again feel welcome on our streets.

I’ve mentioned closures with concrete barriers. What I have in mind is pieces of K-rail, the concrete barriers that one sees at construction projects, to separate motor vehicle traffic from the construction area. They are ugly, and they tend to become worse with reuse, gradually deteriorating into rounded hunks of concrete, but they are relatively cheap and widely available. They also require simple installation. Vertical delineators are somewhat more expensive and require more complicated installation, but are more aesthetically pleasing. Of course concrete is most effective, since vertical delineators can easily be run over by drivers, but I still prefer delineators. Other cities have used a number of creative solutions and objects to reduce roadway capacity, and to keep motor vehicle out of places they don’t belong, so there are widely available ideas on the Internet.

complete streets failure

Dan AllisonLeave a comment

Summary: Complete streets concept is a failure because it doesn’t address frequent safe crossings. It leaves streets dominated by motor vehicle traffic while not necessarily increasing safety or welcoming design for walkers and bicyclists.

A recent post on Strong Towns (Ager Road: Where Complete Streets Fell Short) shows a street that was converted to a ‘complete street’, and won awards, but is actually less safe and less pleasant than what was there before. A fatality occurred shortly after the conversion, perhaps as a result of the conversion increasing vehicle speeds, perhaps not, but the conversion did nothing to reduce the likelihood.

From the post: “This is a stroad in disguise,” remarked Strong Towns Director of Community Action Edward Erfurt when examining Ager Road in Hyattsville, Maryland. And a Twitter post below.

My response:

The complete streets concept is largely a failure, everywhere it is implemented. I’m sure the original intentions were good, but every complete street project I’ve seen affirms the primacy of motor vehicles over other modes. The greatest failure of all is not what happens along the street, but that the concept does not even address the need for frequent safe crossings of the roadway. No wonder traffic engineers have embraced the concept – it allows them to continue motor vehicle dominance and accept traffic violence.

Dan Allison

So you can see the present ‘complete street’ more clearly:

Google Street View of Agar Rd, referenced on Strong Towns
Google Street View of Agar Rd, referenced on Strong Towns

The complete Streets concept is all about travel ALONG streets. Though it recognizes that crossings of streets are important, and encourages designs that make crossing safer and more welcoming, it does NOT address the frequency of safe crossings. The Complete Streets Coalition, part of Smart Growth America, does not require that complete streets policies include anything about the frequency of safe crossings. And so nearly all polices do not address that. The Caltrans policy, which applies only to state highways but is often applied to other streets, does not mention the frequency of safe crossings.

Traffic planners and engineers have embraced the Complete Streets concept, and tout policies and implementation. But what do we really end up with in most cases? Just more motor vehicle dominated streets, which is what most traffic planners and engineers want anyway, and claiming a complete street isolates them from criticism of the roads being designed and built, while making it more likely that they will be a federal, state, or regional grant for their project. Very few projects are awarded grants these days unless they claim to be a complete streets project. That is good, but the bar is set so low for what can be called a complete street, that the result is just more car infrastructure.

The project shown in the Strong Towns post checks off the following elements:

  • sidewalk, check
  • bike lane, check
  • green paint, check
  • general purpose lane(s), check
  • fence to prevent walkers from crossing any place other than the signalized intersection, check (I put this here with tongue in cheek)

What it does not check:

  • narrow the travel lanes to calm traffic
  • reduce the speed limit or actual speed through design
  • remove slip lanes (ask any bicyclist how they feel about bike lanes that cross high speed slip lanes)
  • reduce the corner radius at driveways
  • install or maintain street trees to calm traffic and provide shade for walkers
  • widen sidewalk buffers to ensure healthy trees and vegetation
  • create a pleasant walking environment
  • provide wayfinding to the nearby Metro station

The next time you hear a planner or engineer mention ‘complete streets’, hold on to your wallet (because, after all, it is your tax dollars that fund ineffective projects), and look around you to identify the traffic violence that will remain or even be increased.

The first step in designing a safe and welcoming streets is top ensure that there are safe and welcoming sidewalks and crossings of the street. Everything else comes after that, if at all. Adding bicyclist facilities that are neither safe nor welcoming, and reducing the the environment for walkers in trade, is going the wrong direction, and will lead to less walking and more traffic violence.