Center lane closure
The first alternative Minnesota DOT would explore when projects require center lane closure would be to completely close the roadway over the weekend(s) or other non-peak times when a total closure would be practical. In the metro area, it is common for these total closures to start at 8:00 p.m. on Friday with the work completed and roadway open by 5:00 a.m. on Monday. These contracts include penalties for not having the highway open on time and sometimes include incentives to be done early. They prefer this type of operation when possible, even if it takes several weekends to complete the project. There is little danger to the workers from intruding traffic, the contractor has the entire facility making material delivery and control of work easier, and they get a higher quality of work for less money in a shorter time.
If complete closures are not possible or are impractical, the next alternative would be to work during lower-volume periods when it is possible to close the two right lanes and leave only one lane open for traffic. Typical applications of this type of closure can be found in Minnesota’s Field Manual for short and intermittent term operations.
In urban areas, it is often advisable to close the left two lanes rather than the right two lanes since you can leave exit and entrance ramps open and you do not encourage traffic to cross through the work space to try to exit or enter the highway.
If it is necessary to carry two lanes of traffic and use the left shoulder as a lane, MnDOT would have the same concerns that arise regarding the use of tall cones or tubular markers between traffic lanes and would recommend against their use. In short-term operations (one work shift or less), revision of pavement markings would be impractical.