Friday, April 13, 2012



A question about considering roundabouts at the two intersections involved in a sidewalk project along the Underhill (VT) village section of VT 15 arose during a presentation at the recent Walk/Bike Summit in Burlington. Good question!

The approach taken today for current “roundabouts only” policies at first glance applies to existing and new busy urban intersections serving walkers, including practically all signalized intersections which by nature are “busy.” But installing a first up-to-date sidewalk in the Underhill in a typical rural village center area and also addressing associated intersections with roundabouts at affected intersections? With a series of bicycle and walker projects installing new or major upgrades of existing sidewalks for safety the question of insuring walker safety at associated intersections largely has been ignored.

Federal Highway Administration (FHWA) points to sidewalks as a high level safety treatment which reduces walker injuries by almost 90%--and separately we know single lane roundabouts also reduce walker injuries by a similar 90%. In fact with about 2,500 roundabouts in the U.S. now and “roundabout years” about 13,000 not a single walker fatality has yet occurred.

The Underhill sidewalk project extends about a quarter mile along VT 15 starting at the Park Street intersection and extends just past another busy intersection, Meadow Lane. The sidewalk clearly makes sense and fits the Underhill needs in the rural built up community area and in part replaces an old rundown sidewalk.

Clearly the two intersections in question meet the “busy” category with entering traffic numbers somewhat below the first Vermont roundabout, Keck Circle in downtown Montpelier. Just as clear roundabouts at the two intersections would bring a substantial safety benefit to the sidewalk users. At least one of the Underhill intersections appears to offer no serious right-of-way issues for a roundabout. It should be noted that roundabouts traffic calm by reducing speeds up to 900 feet away along each leg. And for car occupants the single laner also reduces serious injuries by 90%. The VT 15 roadway in question current speed limit of 35 mph also suggests needs to moderate speeds at crossings used by walkers which a roundabout can offer. Across the Lake Champlain the New York State Department of Transportation (NYSDOT) installs only roundabouts at new or existing intersections since that policy policy took effect in 2005.

The landmark U.S. roundabout study by the Insurance Institute for Highway Safety found anything but a roundabout generates on average a 900% greater rates of serious injuries and fatalities. The American Automobile Association (AAA) last November calls for creating a national highway safety policy starting with a goal of a “zero fatality rate.”

One question we need to ask is should we be building new sidewalks whose goal is safety for walkers without building “safe” intersections, i.e., the roundabout, for those same walkers to use? The Underhill sidewalk project cost estimated in 1997 at $360,000. Two roundabouts would more than triple that cost but also provide increased safety to car occupants as well as walkers. Obviously one can argue that the best use of scarce transportation dollars is to invest in converting busy urban signalized intersections to roundabouts—and certainly prioritization of intersections investments would tend in that direction, i.e., the more walkers and vehicles the higher on the list for converting the intersection to a roundabout. On the other hand a roundabout project is “one and done” generally never requiring expensive maintenance and periodic updating typical of the now obsolete signal treatments.

But what of Underhill and a new sidewalk and two busy rural but busy intersections? Can one neatly divide the issue of safety for walkers provided by the sidewalk from the relative unsafety of the two signed controlled intersections which are part and parcel of the Underhill sidewalk route? Do we want to build new infrastructure unsafe for our children? Because there are lots benefits to a roundabout from increasing business access to car occupant safety, then installing roundabouts make sense as part of any new walking facility which connect with or passes through busy intersections The Federal Highway Administration in safety investments values a life saved at $6.0 million (2009 dollars) and $126,000 for an injury.

Vermont's roadway and street policy became muddled last year as it adopted a mis-named “complete streets” law, better described as an “incomplete streets law” which may fairly deal with street sections but totally ignores safety at intersections. The intersection issue in the law can be addressed by adding a policy similar to the NYSDOT “roundabouts only” regulation, and providing guidance regarding new sidewalk projects—such as Underhill—by addressing associated intersections at the same time for “safety” for walkers (and by default car occupants).

Snow plowing and large truck movements often get attention as reasons not to build roundabouts even though neither has any basis in fact. The Vermont Agency of Transportation (VAOT) regularly plows roundabouts, a single laner in East Barre on US 302 and a two laner at the I 91/US 5/VT Brattleboro interchange built more than a dozen years ago. As for trucks 42 daily pass through Keck Circle in Montpelier and 84 tractor trailers through the other Montpelier roundabout at the US 2/302 intersection. The Brattleboro two-laner handles over 900 tractor-trailer trucks daily.

The citizens of Underhill deserve a walker-safe facility and that means the new sidewalk and roundabouts at one or both of the two busy intersections. In this case of walker safety half-a-loaf is not better than one.

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