Funny that the pickup and the SUV stopped, Obviously it would have been a large tall truck behind them that triggered the warning sensors. The truckie must have been blind not to have seen all of the warning sings and flashing lights a mile back before when he could have exited. The sensors which activate the water sign are placed after the last exit if the truck makes it all the way to the curtain then it can take police hours to get him backed up to an exit. I don't know if the proposal to have automatic traffic diversion barricades installed were or will ever be done, in an effort to stop all traffic to allow police much easier way to help the truck back out. You can imagine the fine the driver and company face when this happens. But that is still better than having a truck stuck in the tunnel.