NH's crumple zones: State lists intersections where caution highly urged
Exceeding expectations rather than simple numbers can land troubled intersections on a state watch list each year.
Two intersections in Nashua each saw nearly 100 traffic accidents in 2011, but it was one in Lebanon topping a state list of intersections with the most number of injury-related crashes that exceeded what statistically should have been expected.
State transportation officials use the list to identify intersections to investigate.
"These have more accidents than we would expect, which leads us to believe there is an issue with that intersection," said Bill Oldenburg, administrator of the state's bureau of highway design.
The top 10 list featured five intersections in Manchester, three in Nashua, one in Plaistow and the top one in Lebanon.
Three of the top 10 have already received upgrades, two are slated for changes this year and five haven't been looked at or won't receive any modifications, according to Oldenburg. Variables considered include the type of intersection (whether three or four roads form an intersection), the number of crashes involving injury and the traffic volume each intersection receives.
The intersection with the greatest number of crashes in 2011, regardless of injury, occurred at Routes 101A and 122 in Amherst, with 102 crashes. That same intersection ranked No. 68 on the most troubled list.
According to the state Department of Transportation, there were 30,861 crashes on New Hampshire roads in 2011, 6.3 percent fewer than in 2007. The state Department of Safety cites a statistical average of about 4 out of 10 reportable crashes (those involving $1,000 combined property damage and/or injuries) result in injury.
A state report released last year said 70 percent of fatal speeding crashes in 2009 happened on curved roadways, 65 percent on town roads and 25 percent at intersections. Of those fatal crashes, 45 percent involved alcohol.
When it came to addressing the most troubled intersections, the state used $20 million in federal stimulus money to widen bridges to accommodate a wider Route 12A in Lebanon, including providing dedicated left-turn lanes and traffic-signal arrows at the intersection of the Interstate 89 Exit 20 southbound ramps.
That intersection saw 78 accidents in 2011, including 15 with injury.
Lebanon police Lt. Scott Rathburn said his department has noticed a difference. From September 2012, when the project was essentially completed, through December 2012, the intersection recorded only three accidents compared with 12 during that same time frame in 2011.
"You always want those dangerous intersections off the list," Rathburn said.
In Manchester, the intersection of Bridge and Beech streets, fifth on the list, was improved in 2012 for $103,000. Motorists relying on traffic signals mounted on pedestals on the sidewalk now use signals on metal poles hanging over the street.
"It has been made safer," said Bruce Thomas, a design engineer with the city department of public works.
Two other city intersections on the list will be improved this year, with those projects being advertised to contractors in about a month, he said.
Changes to the intersection of Cilley Road and Beech Street are estimated to cost about $130,000 and involve changing the traffic signal location and "realigning the intersection a little bit," Thomas said. Manchester police reported a two-vehicle crash with injury there Saturday morning. (See story, Page A2)
Signal light and other improvements to the intersection of Maple and Spruce streets are expected to cost about $126,000.
Those three city projects received 90 percent federal funding.
Oldenburg said the state works with communities to spend about $6 million a year on improving troubled intersections and road segments and implementing other safety measures.
Thomas said he was surprised Weston Road and South Willow Street made this year's troubled intersection list, ranked second. The other Manchester intersection on the list was at South Willow Street and the westbound ramps of Exit 1 of Interstate 293. Oldenburg said no improvements are likely there.
In Plaistow, the intersection of Route 125 and Garden Road was modified in the last year or two, according to Oldenburg. Crews installed a median on Route 125 that eliminates cars turning against oncoming traffic, he said.
In Nashua, police said the three intersections making the list all are high-volume traffic areas.
Nashua police Lt. Bryan Marshall said motorists heading south on Main Street who want to take a left and head east on Route 111 must wait for a green-arrow turn signal or obey a sign directing them to yield to oncoming traffic at a solid green light.
"The thing is they'll just look and see green and not literally look at the two northbound lanes (on Main Street) in front of them and get t-boned," Marshall said.
At Route 101A and Somerset Parkway, there are two dedicated lanes to go west on Route 101A, and people can make a legal right on red. Some cars make the right and others hesitate, resulting in crashes.
"That is a huge-volume intersection, and a lot of those are rear-enders," Marshall said. Eliminating the right on red would back up traffic considerably during peak times and would make it difficult for police to pull over violators on busy Route 101A.
At Main and Canal streets in Nashua, vehicles "cut directly in front of oncoming traffic," Marshall said.
A separate ranking of road segments pegged a 1.2-mile stretch of the F.E. Everett Turnpike northbound, between the Exit 5 off-ramp and on-ramp, as the state's section of urban pavement with the most injury-related crashes above statistical expectations.
Nashua police's Marshall was surprised, saying he sees more crashes heading south near Exit 5E.
But Oldenburg said it's not about pure numbers - but about areas that exceed what's expected.
The most accidents on a single segment, without factoring whether they resulted in injury, was found on Interstate 93 northbound from the Exit 4 on-ramp to the exit 5 off-ramp with 277 crashes in a 3-mile stretch. That area is slated for widening and rebuilding in the coming years as part of a larger interstate improvement project.