Road audit finds danger but offers no solutions
Photo by Ralph Stewart
The final Road Safety Audit report of the Massachusetts Department of Transportation (MassDOT) — performed at the urging of West Tisbury and Martha's Vineyard Commission officials — concluded that the intersection of State Road and Old County poses a danger to motorists. The report suggests a number of remedies, however it does not make any recommendations for correcting the situation.
The document submitted to town and island officials on August 10 identifies five traffic safety issues at the intersection as noted during a site visit by DOT traffic safety and highway construction engineers in July: The geometrics, speed of travel, sight distance, driver confusion, and limited stacking for Old County Road. (The Road Safety Audit may be found on the MV Times website at www.mvtimes.com)
The Road Safety Audit was formally requested by the Martha's Vineyard Commission (MVC) at the urging of the West Tisbury selectmen after a three-car accident at the intersection on May 19. Because State Road is a Commonwealth highway any changes to its design must be initiated by the Commonwealth.
The current geometrics or design of the intersection creates an alignment of Old County Road and State Road, [which] causes westbound left-turning vehicles to turn from a number of different points due to the large area of pavement available to accept them on Old County Road." Motorists were seen to make "a sweeping turn and nearly encroaching on the northbound lane for Old county Road, while other vehicles were observed beginning their turn further westbound and making more of a 90-degree turn and encroaching on the painted gore [triangular] area between the two-way segments of Old County Road."
A crash study conducted between January, 2005 and through May, 2010 recorded seven crashes, including four making a left turn from State Road onto Old County. The intersection crash rate is 0.39 per million vehicles entering the intersection. The state crash rate average is 0.87 and the district 5 crash rate average is 0.66.
The Audit states that excessive speed is a safety concern as well. "The smaller deflection angle for turning vehicles allows drivers to navigate the turn at a higher rate of speed than if they had to slow down to make a 90-degree turn." The DOT speed data collected in July 2009 recorded an average of 42-mph for westbound State Road motorists, 44-mph for eastbound State Road motorists and 44-mph for Old County Road motorists. The speed limit on State Road is 40-mph in both directions and on Old county Road 25-mph within 600 feet of the intersection.
Driver confusion because of a lack of directional signs in advance of the intersection is also an issue. The Audit team noted that summer visitors may be unfamiliar with the roadways, and that local police stated that drivers are seen to pull off the road to consult road maps or use cell phones for directions. However, the Audit states that "it should be noted that all but one of the crashes reported at the intersection involved Martha's Vineyard residents."
Limited stacking for Old County Road, or a short amount of pavement space for motorists to wait to make a left turn onto westbound State Road from Old County, is also cited as a safety issue. "Northbound vehicles waiting to make a left turn onto State Road may queue across the southbound lane, which would cause State Road westbound left-turning vehicles to slow for the blockage. These left-turning vehicles could then potentially be struck by eastbound through traffic on State Road. "
The Audit Report provides eight potential short-term (less than a year to complete), low cost (less than $10,000) remedies for the intersection. No mid- or long-term solutions are provided in the Audit.
It is suggested that the intersection striping be modified to create a T-shaped intersection. However the Audit team suggests that changing the striping would not change drivers' behavior when approaching the intersection "therefore this potential improvement should only be considered in conjunction with curb or berm along the southeast corner to reduce the available pavement for the Old County Road approach."
Other possible remedies mentioned: Reapplying existing markings, adding a yellow dotted guide line along State Road and widening to 24 inches the stop lines on Old County Road.
The report also suggests the installation of delineators on State Road. In June the DOT denied the town's request for installation of tube-shaped lane delineators.
In mid-July the delineators were installed, existing yellow lane markings reapplied, and the Old County Road stop lines were widened.
West Tisbury selectman Richard Knabel told The Times that these three steps have already made a difference. "The delineators have slowed people down, it is much more orderly out there, and people are paying more attention to what they are doing."
The Audit also discusses the construction of a raised island along Old County Road to create a physical barrier to define the turning path for westbound left-turning vehicles and to separate northbound and southbound traffic at the stop line. Any improvements to Old County Road are a town expense.
The Audit team also considered the feasibility of an island on State Road but concluded "that it is not a viable short term improvement because it would require widening State Road to meet minimum lane width and island size requirements."
Another short-term low cost improvement suggested is the posting of a street-name sign on westbound State Road in advance of the curve-warning sign. Removing trees on the north side of State Road on the Land Bank property and removing the object marker on the vegetated island "to avoid confusion" are also included in the Audit report.
The Audit states that the long-term improvements for the intersection, as provided in the past by both DOT and the MVC, while discussed during the onsite audit process resulted in "little to no consensus." Mr. Knabel said that a year-long monitoring process is now underway because "we mutually agreed that we want to see how this arrangement works. No one thinks that what is out there now is a permanent fix. But we do want to see how it works."
A long-term redesign of the intersection has been under consideration since 2007 when the DOT submitted two proposals to the town that were rejected. In June the MVC presented three alternative designs to the selectmen and these are currently under consideration. However, once a final redesign of the intersection is selected, it is estimated that any state funding appropriation for road work on Martha's Vineyard would place the project three or four years away.