Is I-91 rotary any safer?
Recorder/Paul Franz Rotary traffic from the west side looking east
GREENFIELD — It has been about three years since upgrades to the Interstate 91 rotary on the Mohawk Trail were completed, but it is still a little too early to tell if those improvements are making a significant difference in how many accidents occur there each year.
According to an early study done by the Franklin Regional Council of Governments, the number of accidents there each year has been slightly reduced.
In the study done the year after improvements were completed, the FRCOG reported that the average number of crashes on the rotary between 2005 and 2007 was 13, and the first year after improvements were made there were eight crashes there.
Stacy Metzger, transportation engineer for the FRCOG, said crash data is limited, because there is no data for “fender benders.” So, the data only comes from crashes that involved $1,000 worth of damage or injuries or fatalities.
According to the FRCOG, Greenfield police, and the state Highway Department, which oversaw and paid for the $1 million project, the rotary will need to be monitored and statistics for the three years following the completion of the upgrades will need to be collected to see what’s really going on there.
Metzger said that study will begin sometime between October of this year and September of 2014.
The project was completed after the state did a $1.1 million upgrade to lighting around the rotary in the spring and summer of 2010.
The majority of crashes that have happened there over the years have been rear-end collisions, and still continue to be, according to the study.
An average of 77 percent of crashes there before the improvements were rear-end collisions, and that number actually rose to 88 percent after the improvements were completed.
Greenfield Police Lt. Todd Dodge said police haven’t seen a marked difference in the number of calls they receive from the rotary.
“We’re chasing our tail there, it seems,” he said. “I think in some ways the improvements, especially the road markings, have confused and frustrated people.”
Dodge said that the majority of rear-end collisions happen as drivers merge into the rotary.
“The driver in front starts to move into the rotary and the driver right behind him thinks he’s gone,” said Dodge. “Therefore, the driver behind hasn’t been paying attention to the fact that the driver in front stopped quickly to let a car going around the rotary move through.”
Dodge said the driver behind the one that began merging is looking to his left to see if there are other vehicles moving around the rotary that he should wait for, and “the driver behind steps on the gas and goes into the back of the car waiting.”
According to the FRCOG, and the state, it is too early to fully conclude that the reduction of crashes there is a result of the improvements, and that’s why another study must be done.
Dodge said a way needs to be found to keep drivers’ attention on the drivers in front of them, while they watch for merging traffic.
The study determined that environmental conditions do not play a large role in rotary crashes, because the majority occur during daylight, when there is clear weather and dry roads.
According to the report, what has not changed is that most crashes happen during peak hours on weekdays, when there is more traffic.
Most crashes occur during July, August and September, again when there is a higher volume of traffic. Most occur on Tuesdays and Fridays, but no reason has been found for that statistic.
The upgrades were made by the state to improve traffic safety through the reduction of crash frequency, as well as severity, and the state also intended to reduce speed around the rotary.
It seems that no matter what speed limit is posted there, drivers tend to go between 30 and 40 mph around the rotary.
It is estimated that about 20,000 vehicles travel on the Mohawk Trail to the east of the rotary and about 22,500 travel to the west of the rotary each day.
The FRCOG also estimates that about 34,000 vehicles travel through the rotary each day and two-thirds of them enter from the Trail. The rest enter from the highway above.
According to the FRCOG, rotaries are notorious for the number of crashes that happen on them, as well as for poor traffic flow resulting from congestion.
Before the improvements, the rotary was ranked by the state near the top of both regional and statewide “high crash” location lists.
It was also ranked by the FRCOG as the most hazardous intersection in the county from 2004 to 2006, and was consistently ranked in the top five from 1995 to 2004.
The state, FRCOG and police continue to hope the improvements will eventually reduce delays around the rotary, as well as rear-end crashes as people become more familiar with the configuration.
The bulk of changes that were done to the rotary included adding pavement markings and directional signs, and widening the roadway around it. There were also pedestrian improvements made by adding and repairing sidewalks.
“They’ll have to keep looking at the rotary, because we are still seeing some of the same problems,” said Dodge.