Permitted movements of oversize and overweight (OS/OW) loads traditionally occur during the daytime on weekdays to allow for adequate staffing support and safety-focused practices. Due to increases in traffic congestion, safety concerns over fleet mixes, and other factors, many states began allowing or requesting those movements to occur during off-peak traffic hours, including nights and weekends. The TRB National Cooperative Highway Research Program's NCHRP Synthesis 572: Night and Weekend Movement of Oversize/Overweight Loads presents the state of the practice for regulating night and weekend movement of OS/OW loads among state departments of transportation.
