Have on every "Exit" marker a yellow light that "flashes" to warn the motorist of a forthcoming bad traffic jam. Might not be practical in urban areas (radio broadcasts and overhead signs would be more efficient), but in rural areas, it would provide the motorist with the option to get off of the expressway and seek an alternative route before becomming stuck in traffic for hours on end due to a bad accident or road construction.

The system could also be applied to on-ramps as well...warning those about to get onto an expressway that clogs before there is an opportunity for them to get back off.

Brings new meaning to the phrase "pitting under caution"!
-- muzer, Oct 06 2003

Something similar is installed on the M90 southbound, just before the Forth Road Bridge (UK). At the side of the road are a series of reflector poles, spaced about 100 yards apart. When there is a traffic jam ahead (because of an accident or due to weight of traffic) yellow warning lights on the poles start to flash. I think the system is still experimental, and is there to stop you rear-ending someone if you suddenly encounter stationary traffic (the road is quite twisty, with poor forward visibility, and with a 70mph speed limit). As almost all of the traffic wants to cross the bridge though, there is little chance of finding a detour.
-- suctionpad, Oct 06 2003


and the crowd goes wild!!??
-- dickity, Oct 06 2003


For the M6 in Birmingham UK, there is a device carried in most cars that informs you if it is congested. It's called a clock.
-- oneoffdave, Oct 06 2003



random, halfbakery