WALKER SAFETY AT ROUNDABOUTS--GETTING THE FOREST AND TREES RIGHT

FORESTS, TREES, AND WHY ROUNDABOUTS INCREASE WALKER SAFETY

During a meeting with a Burlington (VT) city official this week, I was asked to give a concise reasoning of how roundabouts increase safety for walkers.  In response quickly went into the studies, statistics, etc., but forgot entirely the basic element which reduces the frequency and severity of walker injuries: roundabouts by design reduce the speeds of vehicles.  Only by lowering speeds of vehicles can one begin to address walker safety—and the only way to reduce vehicle speeds is with concrete and steel impediments which roundabouts and other traffic calming devices provide.

The roundabout reduces speeds by forcing an approaching vehicle to divert from a straight line through placing a splitter island at the approach point with a curb as the enforcer.  After entry, the vehicle continues to face constraint by having to travel on a circular curbed travelway—the smaller the overall roundabout, the lower the circulating speed.  The entry and curved circular travelway constraints on speed are called “deflection.”  The one factor in all walker safety research which most impacts on walker injury frequency and injury severity is speed.  The small mini-roundabout (like the first one in Vermont built in Manchester Center last fall) features a humped area in the place of a curbed central island—but a mini generally can only be located at an intersection which has a fairly low speed environment.  And a mini only gets employed where a roundabout with a curbed central island is not practical.

Of course other features of a roundabout aid in the overall walker injury reduction—the splitter island providing a mid-crossing refuge so the walker deals with traffic from one direction at a time, the location of the crosswalk a car length from the actual intersection so there are not left hand turning traffic issues, and crosswalk width relatively narrow both reducing walker exposure and assisting in speed reduction of vehicles.

So with roundabouts you do get up to a 90% reduction in injury rates for walkers, and the U.S. and Canadian roundabouts record so far (no fatalities to date) approximates that of France where they yearly average about one walker fatality per 15,000 of their roundabouts yearly (well over 30,000 there today).

Hope this gets the forest and trees back into proper perspective.

NO ROUNDABOUTS--NO SAFE URBAN WALKING

IMPROVING BUSY BURLINGTON AREA INTERSECTIONS FOR WALKERS MEANS ADDRESSING ROUNDABOUT CONVERSIONS OR STRONG TRAFFIC CALMING

            No roundabouts--no safe urban walking 

After observing early planning for “improvements” to intersections on South Burlington’s Shelburne Road and Burlington’s Colchester Ave./Prospect St./Pearl St. one gets a clear view that walkers receive no safety boost and walker fatalities and serious injuries will continue unabated.

The intersections studied in a preliminary fashion over the past few months appear headed for new traffic signals which tend to orchestrate injuries and fatalities, not mostly end them.  Modern roundabouts, that new technology employing stone-age materials, cuts all fatalities and serious injuries by about 90% with single lane roundabout on average cut walker injuries by about 90%.  From another standpoint, any intersection but a roundabout or strong traffic calming generates serious injuries and fatalities overall by an average of 900%.

In regard to Shelburne Road, a Price Chopper employee on her way home died in a walker crash at the Burlington signal intersection with Home Avenue adjacent to the South Burlington border.  The long term plan calls would require two lane roundabouts which the South Burlington consultant rejected as they would require expensive right of way—and the consultant asserted he was not sure about two lane roundabouts and walker safety.  No walker has yet died in the U.S. and Canada after about 12,000 to 14,000 “roundabout years”, duplicating the experience in France with their over 30,000 roundabouts where about one walker fatality is recorded per 15,000 roundabouts each—about a quarter of U.S. and French roundabouts are multi-lane.

The numbers at Colchester Ave./Pearl St./Prospect St.(north and south) include in a five year period two walker crashes and three bicycle crashes.   The intersection boasts one of the highest crash rates in the State.   Without any serious consideration, it appears a roundabout will not even get analyzed for placement at this intersection even though a serious injury was recorded last year at Union St. and Pearl St. and Sam Lapointe received fatal injuries at Colchester Avenue and Barrett Streets. 

A recent AAA study proved highway injuries and fatalities a higher cost to metro areas than congestion and in the case of large metros the differential is more than two to one.  AAA suggests a White House conference on safety and adoption there of a “zero fatality rate” goal for the nation.   For walkers—and they must get prime consideration in any urban area in terms of service and safety—the sidewalk network provides a high level of safety along street segments but only a roundabout or strong traffic calming (like the Church Street Marketplace intersections, for example) provides safety and comfort for crossings. 

Even the Vermont Strategic Highway Safety Plan contains only one infrastructure investment among seven safety initiatives to improve safety: roundabouts at intersections. 

Then what to do in the case of Shelburne Road and the Burlington Road intersections?  The first requirement in both cases must be evaluation of feasible roundabout designs as part of any scoping study.  Since a fatality cost gets a Federal Highway Administration (FHWA) social cost value of $6.1 million (1999 dollars), right of way and related costs may well come in quite high—but so does the cost of a life (FHWA uses a figure of $126,000 for an injury).  So far, no recognized roundabout design firms or designer has been involved in either of the cities studies even though most of the handful of pioneering roundabout practitioners since the era began in North America in 1991 have undertaken one or more tasks in Vermont, such as workshops and training, feasibility studies, and actual design or design assistance one or more  of the nine roundabouts now in place here. 

Note that with two states and two Canadian province transportation departments (including New York) adopted the roundabout the standard intersection treatment, and Vermont’s first in the nation requires that roundabouts be considered at dangerous intersections.  Governor Peter Shumlin in 2002 entered the historic first language in the transportation bill.  The recognition of roundabouts value over signals has been affirmed by adopted laws, policies, and practice not just through research.

In the case of the intersection at the corner of the UVM green, a roundabout which promises to reduce walker injury substantially (as well as car occupants) and afford a modest increase in bicyclist safety may not provide all desirable left hand movements offered by a signal—something that can only be determined by scoping.  A mini roundabout can also be considered.  But, if our first concern is safety at intersections a honest analysis by a competent roundabout design team needs to take place at the scoping level.  Then—and only then—can any citizen process, armed with the complete information, make a truly informed decision on what path to proceed to improve the safety and service at the Colchester Ave./Pearl St./Prospect St. intersection.  Ditto for Shelburne Road and other intersections to be evaluated in the future.

Consultants rejected a roundabout from further consideration at the Burlington intersection because of an “unacceptable footprint.”   Interestingly, there exists plenty of right-of-way at the two intersections along Colchester Avenue, Fletcher Allen Health Care entrance and then East Avenue.  A final aside, while a list of Vermont roundabouts I have maintained has included the traffic circle in Winooski, I am now delisting it.  Normal practice calls for a two lane roundabout to be no more than 180 feet in it largest diameter versus the roughly 500 feet, top to bottom, of Winooski “circle.”  Again, the Winooski design never received analysis and scoping involving a competent, experienced roundabout designer.