Safe Highways and Infrastructure Preservation Act of 1997

Safe Highways and Infrastructure Preservation Act of 1997 - Amends the Surface Transportation Assistance Act of 1982 to revise length limitations on federally-assisted highways to prohibit States from allowing the operation on highways of the Interstate System and the National Highway System of any trailer, semi-trailer, container, or other cargo-carrying unit that is longer than 53 feet, with specified exceptions.

Amends Federal highway law to terminate all current State (grandfathered) exceptions to Interstate vehicle weight limits, unless the vehicle or combination involved is on a list of vehicles and combinations which could be lawfully operated in the State on July 1, 1956.

Directs the Secretary of Transportation to issue regulations, in order to promote conformity with Interstate weight limits for the safety of all motorists, defining the term "vehicles and loads which cannot be easily dismantled or divided" (nondivisible loads), which shall apply to all loads operating on the National Highway System. Sets forth gross vehicle weight and axle loading limits on non-Interstate highways on the National Highway System.