Twenty (20) nights of overnight closures planned for the tunnels as part of a $20-million maintenance project where crews will install a linear heat detection system in each tunnel bore. The work lasts Sunday through Thursday nights for five weeks. One of the tunnel bores will remain open at all times during the project, with pilot cars leading I-70 traffic in alternating directions through the open tunnel. The purpose of the project is to allow staff to better monitor heat levels inside the tunnels. A new suppression system will allow the remote release of water inside the tunnels without staff having to enter.