Thursday, September 15, 2016

What is LTS in bike network planning?

LTS stands for Level of Traffic Stress.

Who wouldn't want to bike with less stress? Even fearless bike enthusiasts who are not afraid to bike anywhere could do with less stress induced by fellow humans who share the road in much bigger devices and could kill you any moment.
Stress free: Bicycling in Copenhagen
Transportation planners long taught the world about VMT (vehicle miles travelled), ADT (Average Daily Traffic) and LOS (Level of Service).

The latest abbreviation, LTS, finally deals with something different than the car: The bicyclist! The idea to plan around stress  is derived from the observation that 70% of the population would consider using a bicycle if they felt safe, but only 13% actually feel safe and only 1-3% use a bike to get to work in real life.

In short, if bicycling could be made so that even more fearful folks wouldn't feel stressed, it is likely to ramp up bike usage. When does bicycling induce little stress? On greenways and trails, on separated bike lanes ("protected lanes") and on roads with little traffic.
Protected bikeway in Vancouver

Bike-planners who try to fit a bicycle network into existing east coast cities with their generally narrower streets have gone through a number of trials and errors. "Sharrows" that indicate that bikes share lanes are not very successful in lowering stress.

They also had to learn that narrow 3' lanes marked along a curb or parked cars does little to free bicyclists from the overwhelming sensation that any second the driver operating a ton or more of steel could misjudge the situation by a few inches and mow you down. Here Portland's, (OR) conclusion:
The Oregon Department of Transportation in 2014, also tracks comfort levels for bicyclists. His analysis found no statistical difference between comfort on busy arterial roads with painted lanes, and on arterials without lanes – painted lanes did not offer people on bikes much relief or perceived protection in the face of speeding traffic. This relation explains the importance of Portland’s decision this past February to establish protected bike lanes as the standard for new biking facilities. (mobilitylab)
Planners also realized, that putting the desired separated bike-lanes in which physical curbs, bollards or a row of cars parked 4'-5' away from the curb separate and protect cyclists from the moving cars, buses and trucks won't fit everywhere. So they built fragments here and there, an approach that they now call "facilities based". That approach leads to bicyclists enjoying a facility will find it abruptly ending just at those points where protection would be most needed.
Low level stress metrics used by Kittelson in
Baltimore (photo: ArchPlan)

With LTS the problem is viewed from the perspective of a network in which cyclists can get from A to B without ever running into high stress points. The solution: The low volume safe neighborhood streets! Once they can be utilized to fill the gaps between real facilities, voila, a network is born.

City DOT asked Transportation planners at Kittelson to develop such a network. A draft of it was presented yesterday to a dozen or so bike advocates at the offices of Bikemore on Maryland Avenue. (In a few weeks Maryland Avenue will be a "bike corridor" with a protected two-way bike facility!).

The draft map elicited a lot of suggestions from those who bike frequently and know the roads, shortcuts and secret connections. Pens in hand the maps were augmented.

A worthy crowd-sourcing approach to improve the GIS based map that showed quickly that the simple electronic mapping approach has a number of pitfalls:
  • Roads with single lanes were automatically considered low volume in the faulty assumption that the # of lanes would be a proxy for volume. But in reality, there are plenty of one-way two-lane roads such as Park Avenue that are much more comfortable to bike thanks to low speeds and low traffic than many single lane two streets such as Eastern Boulevard and Fleet Street.
  • Existing recreational systems were plopped on to the maps as low stress, even for those sections were they happened on the road in simple striped lanes without protection
  • Safety in terms of crime, visibility, eyes on the street, lighting etc. was not considered
  • The map did not differentiate between pleasant and unpleasant streets, for example street trees or active first retail along the way as a proxy. 
  • the calculated coverage (how much direct access to a stress-free connection from A to B the network provides overall)  is simply based on geometry and not on density and where people live, nor where they want to go (destinations like schools, universities, retail centers, libraries and the like).
Most of these problems can easily be fixed in an age where these attributes are readily available as GIS layers. But even  then, on the ground verification on a bike is needed.
A draft low stress network  map for Baltimore
Photo: ArchPlan

Overall, LTS is a worthy idea because it introduces a human value into the transportation world that is often trapped in the mechanistic thinking of  flow, volumes, delays expressed in sheer numbers that say little about the humans whom the transportation planners presumably serve. LTS is a step towards human based design thinking. 

Introducing the emotional well being of actual people into the equation is something I have long demanded ever since I became active in traffic calming on residential streets in my home-town of Stuttgart 40 years ago. I have tried to introduce it to transit planning as well (what will the transit rider see on her trip?), so far to no avail. As a bicyclist and walker I prefer a pleasant street where something happens over one that is dead and deserted anytime.  I think I am not alone in this. Kittelson has to go back to the drawing board and add the more emotionally charged layers to make the LTS map really plausible.

A few good bike corridors combined with the imminent bike sharing and a (online) map that shows realistic and pleasant routes connecting pretty much everything: Baltimore is on its way to become a much more bicycle friendly city!

Klaus Philipsen, FAIA

Stress free biking in Arlington County, VA
Recording Biking Comfort in Portland
Comfort level map legend Arlington, Va: Easy to understand

The Baltimore map legend? Ahem, what? (photo: ArchhPlan)