Published July 19, 2010

Five state troopers have been struck by cars in recent weeks, most recently on Route 24 in Taunton. Early Saturday morning, an allegedly drunk driver struck Trooper Corey Rose, who was pulled over with his hazard lights flashing.

If you think there oughta be a law, there is. If you see a cruiser on the side of the road, you must move one lane over. There are flashing signs in some towns to remind drivers.

The law doesn’t help much if someone is driving drunk, of course. WBUR’s Curt Nickisch has been following this story and tells me there is a lot more Massachusetts could do to protect Staties on-duty. Research shows more and brighter lights are not always better. Here’s our Q&A.

• Mass. has this “move over” law. Do people just not pull over?

Well, more awareness about having to pull into the left lane on the Pike, for instance, would be great.  But that law doesn’t help when you’re on a two-lane road or highway.  In that situation, people are going to be traveling in the lane right next to the shoulder where cars are pulled over.

• Why do troopers keep getting hit? Because people are drunk?

Drunk driving is allegedly the cause of several of these recent accidents, but believe it or not, police lights may be one reason these types of accidents are happening.

What police departments in other parts of the country have discovered is that more and brighter lights do not make parked emergency vehicles safer! Number one, the natural reaction for anyone when passing an emergency vehicle is to look.  But the problem is, people turn where they look.  True for motorcycles, where the act of turning your body can mean turning the handlebars, but the natural car-driver reaction is to turn the steering wheel in that direction, too.

Picture you’re on a two-lane highway and passing a police car on the right shoulder.  You’re going to look right, and you’re definitely not going to turn left, into oncoming traffic. You’re more likely to shade right, “to be safe.”  That effect is more pronounced if you’re drunk, elderly or fatigued, and it can be exacerbated by bright, distracting police lights.

• Is there research to that effect?

Turns out, studies by the California Highway Patrol and Illinois State Police concluded that having fewer lights actually made emergency vehicles safer.

For a long time, the natural reaction was to add more lights to cruisers, make them brighter. But eventually, you get to the point that other drivers can’t see, are distracted by the strobe light effect and are more lightly to cause an accident.

[pullquote]Picture you’re on a two-lane highway, passing a police car on the right shoulder. You’re more likely to shade right, “to be safe.”  That effect is more pronounced if you’re drunk, elderly or fatigued.[/pullquote]

The color of the lights makes a difference, too. Highway troopers in some states use the red-white-blue light bar to pull over cars, but then they turn on amber lights in back, which are more visible in fog and rain and communicate “caution” to oncoming drivers.

• What can Massachusetts learn from other states?

West Virginia had a trooper accident earlier this year and is moving toward using special LED lights that are brighter the farther away you are, but are not as blinding when you’re close.

A couple of states also allow officers to approach a pulled-over vehicle from the passenger side.  That way they have a better view of the driver in the front seat, but they’re also farther away from traffic and are less like to be injured if that vehicle is struck.

Some states use amber light bars in the shape of an arrow to tell drivers which way to change lanes.  Say you’re on a curvy road. You can’t always tell where an emergency vehicle is parked until you get up close. And light bars are just as bright in front as they are in back, so they can be disorienting.