A vehicle warning system for use in conjunction with road signs proximate a roadway and that are visible by passing motorists. The system has two assemblies, one on each side of a roadway and associated with a road sign. Each assembly has a power source, one or more lights that when lit project light that is visible to a passing motorist, a controller, a light activation device, and a wireless transceiver. Operation of the light activation device of a first of the assemblies causes the wireless transceiver of the first assembly to send a signal to the wireless transceiver of the second assembly, and both controllers to temporarily connect one or more lights of each assembly to the power source for the assembly, to light the one or more lights and thus project light that is visible to the motorist from both sides of the roadway.