At the July 18 Middletown Town Council workshop, the Council was briefed by the Rhode Island Department of Transportation (RIDOT) on options for improving the intersections of East and West Main Streets (2 Mile Corner) and West Main and Coddington Highway.
Two options were presented: 1) install additional traffic lanes and signals, and 2) install traffic roundabouts at both intersections.
Previously, the Middletown Planning Board had voted unanimously to recommend the installation of modern roundabouts.
As a member of the Planning Board, it may be useful to explain how I arrived at my decision, especially since at least one member of the Town Council suggested that the Planning Board decision was reached in “10 - 15 minutes.” I do not think that is an accurate characterization of the way the Planning Board does its work.
The idea of roundabouts at these intersections was the outgrowth of the recently completed Aquidneck Island Traffic Study, produced by the Aquidneck Island Planning Commission. Conducted over almost two years, the Study received over 3,000 comments and was the subject of four public workshops, innumerable interviews, email and website comments. Roundabouts were, almost from the beginning of the study, included as an option for poorly working intersections.
The Traffic Study was discussed with all island Councils and was the subject of regular Planning Board briefings. Over the last two years, RIDOT provided the Board with two briefings on roundabout design and operation as well as roundabout experience. The Middletown Planning staff provided extensive information and I conducted my own research on roundabout experience, which I shared with the Board.
What, then, is the evidence and facts that were available to the Board and formed the basis of the Board’s unanimous decision in favor of roundabouts?
There are now about 2,500 roundabouts in the US. Extensive data from state Departments of Transportation, the Insurance Institute for Safety, and the Federal Highway Administration (FHWA) data are available for installed roundabouts - and the results are consistent.
Automobile Safety is substantially improved. Roundabouts eliminate crossing conflicts, reducing the total number of traffic conflict points, particularly “T-Bone” crashes caused by racing to beat the light, failure to stop at all, or quick left turns in front of oncoming traffic.
Roundabouts reduce total crashes about 35% and injury crashes about 76%. Severe injuries and fatalities are rare, with one study reporting 89% reduction in these crashes and another reporting 100% reduction in fatalities.
Improvements in bicycle and motorcycle safety are less impressive, but they still show significant improvements. Studies in Europe found injuries to cyclists decreased on average anywhere from 5 to over 70%.
Data also show that pedestrian safety is improved. This may seem counter-intuitive, but the properly designed roundabout does several things which improve pedestrian safety. A roundabout slows traffic to 20-25 mph, limits the number of lanes to be crossed, allows the walker to deal with only one direction of traffic, provides a "pedestrian refuge" between traffic lanes and probably most important, improves the predictability and visibility of vehicle traffic.
Studies conducted by the Insurance Institute for Traffic Safety and others reported significant improvements in traffic flow from roundabouts. Vehicle delays were reduced 13-89% and stopped vehicles 14-56%, wide ranges, but reflecting the ability of roundabouts to improve traffic flow and, as an added benefit, reduce automobile emissions by reducing stops, idling and acceleration.
Studies indicate that drivers are often skeptical, or opposed, to roundabouts when they are proposed. However, opinions quickly change when drivers become familiar with them. In general, about 30% of drivers support roundabouts before construction, compared with 60-70% after use.
RIDOT simulations of the proposed Middletown roundabouts are consistent with the experience of other states. The RIDOT simulation predicts the total number of crashes will decrease from an average of 58 per year to 30 (48% reduction). Average injury crashes are expected to decrease from 8 to 6 (25% reduction).
Traffic delays are predicted to be reduced by over 50% and the overall Level of Service to improve from "C" or “D” to "A" or "B". (Level of Service is a grade assigned to an intersection reflecting traffic flow, safety and other factors. LOS’s range from A to F).
These are the some of the reasons and the data that I, and other members of the Board, considered before voting to recommend roundabouts as the better option for the intersections of East and West Main and Coddington. It was a well-researched decision.
Middletown Planning Board Member