The short answer is, no difference.
Work zones are referred to as “Rule 42 zones”. Basically, there is a marked point on either side of the work zone where each train must stop and contact a “Foreman” (no gender implied) by radio for permission to proceed. The Foreman is stationed at the work site (usually in a company vehicle) and, when called by an approaching train, verifies that all workers and equipment are clear of the work site and know not to move foul of the track. When the Foreman is satisfied that it’s safe to proceed, they give the train verbal permission by radio. They may add special instructions, such as a maximum speed through the work limits, where to sound bell and/or whistle, etc. The location of these zones are conveyed to the crews at the start of their shift in writing, and are marked physically in the field by “flags” (temporary signage, actually) and it’s a big deal if the crew overlook the written instructions or fail to spot the flags.
To your question, one foreman can clear more than 10 trains an hour in each direction - as they frequently do already between say Mimico and Bathurst St. The limiting factor is really how much radio traffic can be handled.... it certainly gets difficult in peak hours as all foremen share the same radio channel. Only one person can speak at a time. Of course, this assumes that the track is kept clear - if work requires that equipment must block the track, the train has to wait until the equipment can vacate and permission to proceed can be given.
The issue for nights and weekends is simply that this is when much of the maintenance happens, so while there may be fewer trains there is also less track available.
- Paul