Connecticut’s Department of Transportation recently installed a federally funded proactive safety tool along Bridgeport Avenue to reduce the number of head-on crashes that occur.
DOT spokesperson Kevin Nursick said the bumpy surface that drivers may have noticed when their vehicle began to cross over into the opposing lane are called “Center Lane Rumble Strips (CLRS)” and they have statistically been proven to reduce the number of head-on or crossover- type crashes.
Nursick said he’s anticipating similar results from the nearly five-mile stretch of CLRS on Bridgeport Avenue, applied 1,000 feet north of Huntington Street to Coram Avenue in the downtown area.
“On the low end of the spectrum, crashes were reduced by 25% where CLRS were installed, on the high end of the spectrum, crashes were reduced by up up to 64%,” said Nursick.
He went onto explain that the CLRS were created by modifying a similar form of rumble strips that were strictly used on highways.
“At one point we were targeting rural roads, but now we’re a little more liberal with our application here because benefits can be realized on pretty much any roadway,” said Nursick before he explained the variations to the driving safety tool.
As Nursick mentioned, similar rumble strips have existed on highway shoulders for years, but the slightly modified version of the tool is used to consider the different surroundings of roadways.
“On a highway everyone is traveling in the same direction so the rumble strips there are designed to keep you in your travel lane and to keep you from leaving the driving surface, whether that’s from striking a barrier or colliding with a median,” said Nursick. “Those are called ‘shoulder rumble strips’ and because of the type of roadway and the fact that they’re on highways, we gave them a more aggressive texture.”
The “aggressive texture” Nursick mentions is created by making cuts in the asphalt that are spaced closer together, and are deeper to produce a more substantial feeling and noise when a driver drives over them.
The shoulder rumble strips are designed to produce a louder noise and more exaggerated feeling because they are located on the passenger side of the car, in contrary to the CLRS.
“When you’re talking about CLRS a lot of the time you’re talking about areas that have homes, so noise is going to be a concern,” said Nursick. “The effect is literally taking place right under the driver’s side tires so you can have a less aggressive rumble strip. They’re spaced further apart and they’re less deep so that the noise they cause isn’t as loud. But, you’re still getting the same benefit of the vibration, just with less noise.
In the case of Shelton, Nursick said the DOT did something a little different to the existing CLRS model.
“In Shelton they’re called ‘Sinusoidal’ Rumble Strips,” said Nursick. “Instead of having individual cuts in the asphalt, where you have a small cut and then flat asphalt, you have a continuous Sinusoidal wave pattern in the asphalt so that it’s one constant wave. They produce less noise to neighboring homes or businesses, but they still have the same vibrating effect and noise inside of the vehicle, alerting the driver that he/she has left their travel lane and they need to take corrective action.”
Roadway qualifications for rumble strip installation
In order for a roadway to qualify for the application of CLRS it must meet the following standards: have a speed limit of 35 miles per hour or greater, the paving of the road must have been completed within the past three years, the segment must be for one mile or longer, it must have an average daily traffic rate of 2,000 vehicles traveling per day, and it must be located in a low residential-density area with homes at least 100 feet away.
“You can’t install the CLRS on old conditioned asphalt because the road would just come apart. You’ll lose the asphalt surface and you’ll end up with a degraded driving surface,” said Nursick.
This year alone, the state’s DOT has applied the CLRS in five separate projects for a total of 55 miles of state road and 34 miles of local roads. The total cost of the state’s 2017 CLRS installation is approximately $775,000.
Causes of the crashes
According to Shelton Police’s own Sergeant Mark Ptak, over the last five years there have been a total of 4,700 crashes that have resulted in injuries or property damages, 16 fatals, and two were recorded as head-on collisions. Ptak said from his own experience, he’s noticed a correlation between drivers crossing over into opposing lanes and distracted driving or while driving under the influence. He added that there has been an occasional instance where someone driving suffered from a medical condition and crossed over into an opposing lane as a result.
Nursick said despite the varying numbers of head-on crashes being recorded in different areas, CLRS is a way to make drivers more safe than sorry.
“These crashes are as bad as they get; they often result in serious injuries or fatalities,” said Nurskck. “There’s clearly a correlation between motorists leaving the travel lanes and not knowing it. It’s not a 100% safety net here, but they seem to have an impact on virtually every type of driver in terms of alerting them that they are leaving the travel lane. Even if you’re talking about preventing one head-on crash, that’s well worth the cost because those are the ones that result in people having their lives changed forever.”