THE PROPER BUSY STREET DESIGN--PROTECTED BICYCLE LANES (CYCLE TRACK) WITH ROUNDABOUT INTERSECTIONS WHICH INCLUDE SEPARATE BICYCLE PATHWAYS
Today Vermont and the nation face the reverse dilemma encountered by Western European nations a half-century ago and now only mostly resolved. Then Western Europe with the bulk of urban trips by foot, public transit and bicycle faced an invasion of cars on street systems which in many cases dated from the Middle Ages. Europe largely solved their dilemma through innovations ranging from modern roundabouts, traffic calming, cycle track (protected bicycle lanes) and “shared space.” An equilibrium now exists there in the modal shares with car travel in some areas still a minority of urban trips with walking and bicycling trips even increasing their shares.
Today Vermont like the rest of the nation operates in the beginning of an urban transportation revolution with rapid growth in walking, bicycling and public transit modes—but from a tiny base shares, less than one percent share for bicycle trips, just over three percent for walking trips, slightly over six percent public transit and overall ten percent for these three modes
Since government controls practically all walking, bicycling, bus and rail passenger infrastructure and investments, the urban transportation customer who demands immediate changes to enable their new choices faces a stodgy, unresponsive governmental landscape. And too often that landscape set of choices involves increased risk to life and limb.
The walking and bicycling infrastructure stovepipes
Two key types of new infrastructure of great benefit to walking and bicycling modes—roundabouts and cycle track—arose from separate and distinct histories. Roundabouts arose in 1966 in the U.K. primarily as a means of moving more cars with less car occupant injuries—the fact that walker injuries sharply declined and at most a minor gain in bicyclist safety got treated as a side benefit. Cycle track—now a Western European staple—grew from increased cyclist carnage on busy streets when car travel increased. Yet, roundabouts and other walking and bicycling infrastructure appeared to develop along separate parallel lines. The connection between cycle track primarily benefiting cyclists of all skills and roundabout treatments--which one can argue arose primarily meet the safety and service needs of walkers--remained to a great extent evolving within their own separate stovepipe.
So, in a sense there has existed a “roundabout” stovepipe and a “cycle track” stovepipe. Sidewalks for walkers and cycle track for bicyclists now represent a generally accepted approach for street segments, and several U.S. cities, particularly Chicago now in the midst of installing 100 miles of cycle track leading the development. Meanwhile, the bicycle community justifiably found the larger earlier roundabouts in the U.K. still highly crash prone and that legacy of concern spread to other nations. Research finds bicyclists injury rates decrease significantly over alternatives with single lane roundabouts and slight safety increase at smaller two-lane roundabouts.
Roundabouts came to the United States in 1990 and now number about 4,000. Roundabout performance included an overall reduction in serious injuries and fatalities of about 90%. But for those who walk and bicycle, safety—particularly at multi-lane roundabouts—remained a concern. The “roundabout stovepipe” did not address how to serve all skill levels of bicyclists in a comfortable and safe manner. Only recently has the U.S. design guidance suggested on/off ramps for bicyclists to avoid the roundabout circulating roadway and only then for multi-lane roundabouts. So, the stovepipes developed—roundabouts serving the needs of cars and in smaller versions the needs of walkers while cycle track helped bicyclists of all skills move with a high level of safety between intersections.
Leave it to the Dutch who experimented with pathways at roundabouts and researching the performance before and after for treatments to find an avenue where all modes can operate with increased safety and efficiency at intersections—in a word to resolve the conflicts between roundabout and cycle track stovepipes. The Dutch research revealed that a roundabout with a separate bicycle pathway sharply improved safety over alternatives with or without a bicycle pathway. The bicyclist community cites research which concludes that a separate path (such as cycle track) increases bicycle crashes—but that same study shows the decrease in crashes along street segments provided by the path is overshadowed by increased crashes at intersections—which, no question—would be signs and signals. The pathway/bicycle facility armed roundabout matched with cycle track seems to be the ready resolution of the dilemma and promises a final erasure of the roundabout and cycle track stovepipes.
Ideally, the busy intersection treatment becomes a roundabout with an cycle track approaches on each leg leading to a separate bicycle pathway more or less in parallel to the sidewalk system and side-by-side crossings with the walker crosswalk. Of course, not all intersections possess the space for the ideal of separated bicycle and walker treatment so that multi-use pathways or—at worst for the cyclist—the on/off ramp (the minimum treatment) on the sidewalk where, essentially, the bicyclist becomes a walker.
Dutch roundabout intersection designs now are being circulated as models for bicycle treatments. And, there is no reason why research should not confirm the Dutch experience that properly designed bicyclist treatments at roundabouts along with cycle track along street segments represent the future for urban street design to the meet the needs of bicyclists and walkers.