Rain may have been slowed drivers on Highway 400 between Barrie and Toronto on Friday but so did construction.

The rolling construction zones along the 400 start at Highway 89 and run all the way to Innisfil Beach Road.

The speed limit has been reduced to 80 km/h to protect construction workers and because some places the lanes have been narrowed and enforcing the speed limit is a challenge for police.

“From my personal experience I’ve dealt with people who are travelling 140-143 km/h in the posted 80 km/h zone,” says OPP Const. Greg Crowe.

The problems start when police have to pull them over.

“In the construction zone itself, there is areas where there are very narrow shoulders or sometimes no shoulders at all so it does make it difficult for officers to do enforcement right in those locations,” says OPP Sgt. Kerry Schmidt.

To compensate, police station themselves at the beginning and the end of the construction zones or sometimes follow speeders all the way through until it’s safe to pull them over.

Going 80 km/h is also important because construction zones are changing all the time, especially at night.

“In the daytime there are three lanes, at nighttime they are reduced to two to one, sometimes they put up concrete barriers in place, in other places where it’s only a temporary closure they’ll put pylons out there,” adds Crowe.

The highway is never the same one day to the next and according to the Ministry of Transportation it will be in a state of flux until 2016. The speed limit will be at 80 km/h until the construction is complete. Police say the MTO will be installing more electronic signs to get the message across.