4 ms·
The warning beam is several stopping-distances before the tunnel itself, and far easier to replace/reconstruct. I'd try a 3-stage contact-warning system: (1)
by gojomo 14y ago
The warning beam is several stopping-distances before the tunnel itself, and far easier to replace/reconstruct.
I'd try a 3-stage contact-warning system:
(1) hanging bar that makes noise on contact but causes little damage. This might even go before a suitable turn-off.
(2) breakaway cord with trailing noisemakers. This would be torn from its mast by the collision, and drag noisy items behind, emphasizing the need to stop and investigate.
(3) hard bar providing some slowing/resistance (but almost certainly not full stopping power, given the position and expense). By design this would actually damage the vehicle (and even risk harming the driver), approaching the same level of damage that would occur at functional tunnel-entry. But, it'd happen earlier where easier to clear/repair.
- numbsafari 14y agoAnd yet, with this solution, no repair is needed for either the truck or the infrastructure. The vehicle is able to be removed under its own power, the driver is not injured, there is no debris. If you are in a vehicle behind a truck that has damage to its top, you very likely will have damage to your vehicle from flying debris.
- joezydeco 14y agoOr a ten-ton beam falling on your car.
- gojomo 14y agoOh, I like the water-wall too. But a driver who misses the 1st two no-damage physical-contact warnings I've proposed -- and thus would hit the damaging third hard bar -- would quite possibly ignore the water-wall too. After all, the water wall seems primarily visual, and the driver has already missed numerous visual warnings. The contact protectors add collision-noise and vibration, which are rare enough that even a dozing/road-hypnotized driver is likely to take note. Comparative testing is of course justified.