Friday, April 7, 2017

The lowdown on rolling slowdowns

by Ally Barrera 

I get it. I don’t like sitting in traffic either. But sometimes there’s a need for a specific tactic that may have me tapping my breaks and slowing down on a state highway for a little while in order to keep us all safe. I’m talking about the rolling slowdown.

What is a “rolling slowdown”?
You may be asking yourself, what on earth is a rolling slowdown? Don’t worry, I didn’t understand that term until I recently starting working here.

Rolling slowdowns are when Washington State Patrol troopers or our Incident Response Team crews drive in front of traffic with lights flashing as they gradually slow everyone down to a crawling speed. The trooper or IRT will then slowly guide traffic until the incident or planned maintenance work has cleared. Once it’s finished, the trooper or IRT allows traffic to get back to its normal traveling speed.

Recently we’ve had rolling slowdowns on I-5 in north Seattle while Seattle City Light strung power lines over the freeway, and another on I-5 in Bellingham while we did emergency pothole repair. Those are the kind of jobs where you don’t want vehicles buzzing by you at 60 miles per hour, and in the case of the Bellingham work we were able to patch the hole in about 15 minutes.

Why not just stop traffic?

So what’s the point of just slowing down traffic instead of stopping it completely? Believe it or not, stopping traffic is actually more dangerous.

Think of it this way:

Imagine you’re traveling down the freeway at 60 miles per hour when all of a sudden the traffic in front of you is completely stopped, forcing you to slam on your brakes to avoid a nasty collision. Something like that is definitely going to stop traffic, likely for quite a while as emergency crews respond to the crash.

An example of a rolling slowdown on the I-5 express lane
Rolling slowdowns, on the other hand, have proven to significantly reduce the risk of rear-end collisions because they allow traffic to decelerate to the same speed as the vehicles in front of them, instead of having to stop abruptly.

Keep you rolling along
Rolling slowdowns also usually allow traffic to continue moving – albeit slowly. Generally, rolling slowdowns add about 15 to 20 minutes to your trip at most, and ideally, traffic is never completely stopped.

For example, say we had to close a lane of I-90 through Snoqualmie Pass to clear debris from the road. The traffic delays from closing that one lane could make your travel time significantly longer, as much as 1 to 2 hours during heavier traffic periods. We would have to send out an IRT truck to stop traffic while crews lay out barricades and any other equipment they might need. Once that is set up, then they can finally remove the debris, clean up all their equipment and remove their barricades or traffic control devices.

Our IRT crews or WSP will lead the way during a
rolling slowdown.
This work often doesn’t take more than 20 minutes but in that time, traffic can back up several miles depending on traffic volume.

If we used a rolling slowdown to clear the debris, only 5 to 8 minutes typically would be added to your travel time, and you and our workers would be safer. That seems like a pretty fair trade, don’t you think?

We know that any time we slow down or stop traffic, it’s an inconvenience but please remember that it’s always done for your and our safety. So if you see a trooper or one of our trucks or crews out there on the road, be sure to take the time and give them room to work. Remember, it’s illegal and unsafe to pass an emergency response vehicle while its lights are activated and you are being slowed down, so please be patient. The safer road crews feel, the better and quicker they can do their work.