Time frame allowed for lane closure setup (e.g., 9:00am to 3:30pm)

In Indiana (INDOT), if the language states in the contract that a contractor cannot close a lane till 9am then the interpretation is that all devices can be ready (along the shoulder) to close the lane but cannot be placed in the closure position till 9am. The lane closure cannot be in place prior to 9am.
INDOT has recently developed a policy that 2 lanes must always be open during construction on the interstate system unless the section of interstate under construction is in an area of the state where traffic volumes fall below a certain level. When lane closures are used either on the interstate or state roads, the contract documents often do not address times when lanes may be restricted unless the work is at a location, interstate or otherwise, that traffic would back up greatly if lanes were restricted prior to rush hour or for other reasons. When that is the case, the contract contains special provisions that inform the contractor when traffic can be restricted and all equipment must be off the road. There are liquated damages tied to the restrictions if the contractor closes early or removes the restriction too late. The times of day can vary from contract to contract. Each project is looked at separately and the times are set according to ADT volumes. INDOT is going toward nighttime work only whenever that is possible.