A Bike Priority Route System

Recently, intent observers might have wished for Tom Brady’s wristband to keep track of the dizzying array of terms being trotted out to describe bike facilities that go above and beyond the usual bike lane.  Just in the past few weeks, I have read about bike boulevards, green lanes, “Green Lanes” that aren’t necessarily green, separated bike lanes, bike highways, bike superhighways, the U.S. Bicycle Route System, and low-stress bicycle networks (pdf). The problem with having all these nebulous and overlapping concepts is… Well, actually, that’s precisely the problem right there (and don’t get me started on the green lane/”Green Lane” thing).

Some of the things above describe types of facilities (green lanes that are actually green, bike boulevards), some of them describe systems (USBRS, the bike highway post), and some of them include considerations of mobility (bike superhighways). I am going to cherry-pick all of my favorite bits out of these, mash them together into a hopefully-logical whole, and sincerely invite you to poke some snarky holes in it.

My $.02 of urban bicycle infrastructure, the “Bike Priority Route System,” has three main attributes.  It provides safe and low-stress priority routes (the facilities). These priority routes provide easily-followed connections between origins and destinations, with minimal diversions, within the region (the system). Travelers on these priority routes are able to travel with minimal delay and disruption (mobility). My apologies if this just turns out to be another Belichickian scribble on your grass-stained wristband.

Facilities? Speak English! OK. Well, there’s a segment of US population referred to as “interested but concerned.”  They are the spouse or parent you have been nagging to use their bike to pick-up their takeout or join you for Bike to Work Day, but they just won’t do it. Our existing streets, where bike lanes are damned by the faint praise of offering the highest-available perception of safety, scare most people off their bikes.

Sounds about right. Right? So, what do we install instead? Well, there are a few varieties of places where people who currently do not ride bikes might consider riding, including trails, cycletracks, buffered bike lanes, and bike boulevards. These all have their relative merits and contexts, but what do they have in common?  In short, they offer a more inviting and comfortable place to ride than a bike lane along a busy street.  But the group of esteemed authors of Low-Stress Bicycling and Network Connectivity (pdf) provide a more precise description:

Presenting little traffic stress and therefore suitable to most adult cyclists but demanding more attention than might be expected from children. On links, cyclists are either physically separated from traffic, or are in an exclusive bicycling zone next to a well-confined traffic stream with adequate clearance from a parking lane, or are on a shared road where they interact with only occasional motor vehicles (as opposed to a stream of traffic) with a low speed differential. Where a bike lane lies between a through lane and a right turn lane, it is configured to give cyclists unambiguous priority where cars cross the bike lane and to keep car speed in the right-turn lane comparable to bicycling speeds. Crossings are not difficult for most adults.

This publication moves away from US practice of characterizing facilities strictly by physical traits, like facility type (“trail,” “cycletrack”), or by road characteristics (Level of Service), Instead, it suggests the practice of the Dutch, who characterize the places that people bicycle by how stressful the experience. The description above, for Level of Traffic Stress (LTS) 2, completely encompasses all of those facilities mentioned that go beyond the traditional bike lane.

In the Bike Priority Route System, Priority Routes would be made up entirely of facilities that fit within that definition above. By moving away from strict facility types (“build more cycletracks!”), we can build a complete network by making long corridors that work in a functionally-similar manner down their entire length.  As an example, two disconnected trail segments, connected by a segment of bike boulevard, delivers a functionally-similar experience to my bike-wary-but-willing wife.

System? Is this somehow related to whatever “The Cloud” is? I hope not. There are a few important elements here.  First, to truly be a “system,” a user should be able to get to/from anywhere he/she needs to go on an uninterrupted Bike Priority Route without having to divert too far from the most direct route on the roads. For planners, a huge challenge is to figure out, with scarce data, a prioritization of origins and destinations for bicyclists.

Second, Bike Priority Routes must be easily recognizable, both on a map, and on-the-go. Beyond DC put together a trails map (image pasted below) that conveys the main point of clearly and prominently identifying priority corridors.  However, in a Bike Priority Route System, this map would go beyond trails, and include all Priority Routes, to include some cycletracks and bike boulevards.

Another challenge is wayfinding without a map. The first necessary measure is naming routes memorably, and without regard to facility type. As an example, imagine a corridor cutting across DC, connecting the existing Anacostia, Met Branch, Rock Creek, and Capital Crescent facilities. This corridor might include trail segments across parks, cycletracks that shift from one parallel street to another, and perhaps a bike boulevard segment for auto traffic calming. Asking riders to, “Take X Trail to the cycletrack on K Street, which goes a block north to L at 9th Street…” is hardly low-stress. Rather, call this the “Cross-District Route,” draw it on maps with surface-street reference cues, and prominently and uniquely sign the routes. Here’s an example of a nice bike-specific sign in Vancouver BC (from Spacing Magazine):

The sign is distinct in color and appearance from regular road signs, but the information dominates, rather than the bicycle symbol.  The sign’s mission is to guide a bicycle rider, not to tell drivers that this sign does not apply to them. Compare to the bike navigation sign below, which treats bicycles and drivers as equally-worthy recipients of the message that THIS IS A BIKE SIGN, and then gets on with providing the actual wayfinding info to bicyclists in a Comic Squint Serif font.

(Photo by Laura McCamy, via oaklandlocal.com)

I would guess that there’s a lot of  human-factors testing showing that drivers can easily tell that it’s a bicycle sign, but little/no research on how effective it is at quickly communicating route info to bicyclists.

Mobility? Like a scooter? Actually, sorta, yes. What if riding a bicycle took a little bit less effort and delay, with less of that energy-sapping start-stop nonsense? Kind of like a bicycle mobility-aid. Cars enjoy that luxury, especially on routes that we could easily dub the Car Priority Route System.  On limited access highways, through-traffic keeps moving unimpeded because intersections are grade-separated (with bridges and cloverleaf intersections). On arterial roads, traffic signals are timed to maximize progression (that phenomena where if you travel at a certain speed, you catch a series of green lights). On some other roads, various gizmos are deployed to automatically detect cars, and minimize their delay by giving them a green light (without having to push a button!).

In Washington DC, even our most highwayish bike facilities do nothing like this. Our trails are dotted with stop signs to cross even the lowest-traffic streets. Sometimes they feature stop signs augmented with/ contradicted by traffic signals. Following the law at our cycletrack intersections is rewarded with a “red wave” of delay. Automatic bicycle detectors are rare (possibly absent entirely) in the Washington DC area. Some high-bike-traffic intersections, such as 18th St South and Crystal Drive in Arlington, require a bicyclist to push a pedestrian call button just to obtain a legal opportunity to cross if there are no cars present during non-peak hours. Baseline signal timing schemes often work against bicyclists, not just because of speed differential, but because bike routes are often on streets with relatively low car volumes, which means less green time by design.

This is where designated Bicycle Priority Routes would earn the “Priority” part of the name. Intersections would not simply accommodate bicycles, they would seek to maximize their progression. Like highway cloverleafs (cloverleaves?) minimize stopping through grade separation, bridges, underpasses, and perhaps even a floating roundabout would channel bicyclists over, under, and around stressful intersections. Where grade separation is not possible, a variety of bicycle detectors are available to sense that bicycles are approaching, and give them priority to progress down the corridor as easily as possible. 4-way stop sign intersections are prime candidates for roundabouts.

However, nearly-free interventions are available to provide for Bicycle Priority without having to deploy infrastructure or technology fixes. By tossing aside traditional signal timing practices that call for “balancing” the needs of all users at discrete points, and instead giving preference on a limited number of Bicycle Priority Routes without regard to existing volumes of cars or bikes, we would give bicyclists a few corridors where they can travel with more progression than interruption, as drivers currently expect everywhere. Copenhagen’s famous “green waves” are sometimes activated by technology, but often are simply accomplished by timing traffic signals for bicycle speed, rather than car speed.  On our Bicycle Priority Routes, we ask signal timing engineers to set aside their warrants and timing schemes, and accept that there will be some unavoidable delay for crossing cars, and perhaps even congestion, so that bicyclists may travel on a few routes where they do not have to stop at Every. Single. Intersection. The same principle applies for stop signs. Why does Virginia’s Mt. Vernon Trail feature a 4-way stop wherever the Trail (a high-speed travel facility for bicyclists) crosses a driveway leading to a parking lot?

Notice how I didn’t mention the Idaho Stop until now? The Idaho Stop puts bicyclists in the legally, physically, and (some argue) ethically vulnerable position of having to negotiate their way through intersections in ways that run counter to common interpretation of the traffic controls displayed. It helps meet bicyclist needs in the short term, but its need and implementation is symptomatic of a system that does not accommodate them.

To (finally) sum up — A Bicycle Priority Route System would provide a service promise to those “interested but concerned” folks that they can travel by bike wherever they need to go, on facilities they perceive as safe, will not get waylaid and dumped onto an incompatible 8-lane arterial road, and won’t have to put a foot down at every cross street. There’s nothing revolutionary here – it is simply stuff that we expect when we are in our cars, and without giving it an overwrought label, the world’s best bicycling cities are doing.