Construction crews on Highway 400 are pleading with drivers to slow down.

Highway 400 between Major Mackenzie Road and the Willow Creek Bridge in north Barrie is made up of 36 kilometres of construction zones. The speed limit through these areas is 80 km/h.

"We just arrested a guy this afternoon doing about 170 on the 400 in construction zone. He's under arrest right now," says OPP Sgt. Kerry Schmidt.

Bot Construction has a crews working almost 24 hours a day at the 4th Line in Innisfil. It’s one of only a few spots where the Ministry of Transportation has not mandated a speed reduction.

"You can feel as the traffic is going by and speeders are going by,” says construction manager Mike McMurray.

During the day, a concrete barrier separates workers from the highway, but at night it's a plastic barrel. It’s overnight when most of the speeding occurs.  

Not only are drivers not obeying the speed limits, but many are distracted behind the wheel.

"Any miscalculation by a driver will put it into our work zone and that would be putting our people at risk as well.”

“We're very concerned about it."