Not every night, just Monday through Thursday.
From an email I received last week:
Beginning next week, the cables for the Slotzilla Attraction will be installed.
Then installation will affect both pedestrian and auto travel within and around the mall. The mall will be closed to both as follows:
This install requires road closures on Casino Center (northbound and southbound lanes) and 4th Street (northbound lanes) during the following days, Tuesday, November 5th through Friday, November 8th, 2013 and Tuesday, November 12th through Friday, November 15th, 2013 during the hours of 12:01am to 8:00am each day for the installation of the cables for the Slotzilla Zipline Project through the City of Las Vegas.
Eight Zipline cables – 4 upper lines from 4th Street to Main Street and 4 lower lines from 4th Street to Casino Center – will be installed during the above time frame to complete the Slotzilla Ride.
Barricades will be set up down the entire length of the mall for safety reasons during the installation.
The businesses on Fremont Street Experience will need to close at 12:00am during the above dates. No pedestrian traffic can occur during the installation hours.
From 12:00am to 1:00am, there will be a designated space for east/west pedestrian travel to help facilitate the travel of employees and patrons from exiting the businesses.
Starting at approximately 1:00am, all pedestrian traffic will be excluded from the mall again for safety reasons during installation.
The mall will remain closed to pedestrian traffic until 8:00am."