ST.
 PAUL, Minn. – If you’re traveling down the highway some night, 
particularly in the Twin Cities area, you may notice brightly lit work 
zones and road crews in high-visibility clothing filling  potholes, 
repairing guard rails, pouring concrete, you name it.
Doing
 some road construction and maintenance work at night is one way the 
Minnesota Department of Transportation is minimizing the impact to the 
traveling public and increasing motorist safety. 
“Crews
 can sometimes work more efficiently at night when traffic volumes 
aren’t as high as during the day,” said Michael Beer, MnDOT Metro 
construction engineer. “Night time also is helpful  for contractors to 
more efficiently get materials and equipment to and from a project in 
reduced traffic congestion.”
The Interstate 35W at 94th Street and Highway 100
 projects in the Twin Cities involve bridge redecking work, which 
requires new concrete. Pouring concrete during cooler night temperatures
 prevents it from drying faster than it should and makes for a more 
durable, longer lasting deck, said Beer. 
In Owatonna, another project requires night work so crews can place bridge beams on the newly constructed abutments of I-35. In this project, roads will be closed from 9 p.m. through 5 a.m.
Maintenance projects are also sometimes done at night. MnDOT employs several maintenance crews specifically to work night hours.
“Many
 corridors and routes are so heavily traveled that night time is the 
only time we can do the work safely,” said Greg Coughlin, MnDOT Metro 
director of operations and maintenance. “If  we’re filling in potholes 
or repairing guard rails, we might have lane closures that we can’t get 
by with other than nights or on weekends. At night, we’re also not 
impacting communities and people’s daily business.”
Crews often get projects done faster at night because of fewer traffic interruptions.
“Our
 lane closure policy limits windows of time on many corridors to do 
maintenance work. The 10-hour shifts are efficient since most night 
crews load up and go  from site to site,” said Coughlin.
When
 a significant duration of night construction work is necessary, MnDOT 
sends a letter to people who live or work near the construction zone. 
The letter explains the construction activity,  the expected noise 
levels, the duration of the work, and provides contact information. The 
letter is mailed, emailed or hand delivered to all residences and 
businesses within 500 feet of the work zone. Often, a news release or 
email alert is also issued.
Construction
 activities generally prohibited between 10 p.m. and 7 a.m. include pile
 driving, concrete pavement removal, pavement sawing, concrete crushing 
and jack hammering. There are times,  however, when noise-producing 
operations occur at night due to the need for pavement to be cured or 
sawed.
Coughlin said a risk of night work is the potential of drivers who are tired, distracted or under the influence. 
“With
 less traffic on the road, drivers’ speeds can be greater,” Coughlin 
added. “Motorists should be cautious in work zones at night, slow down 
and be alert for crews working.”