I disagree. I've driving in the worst white outs at night up north over mountains in a car with semis around, if you stop you've caused an accident and made things worse.
I'm not doubting that visibility could of been 0, even if it was, that person that made it to the bridge first and STOPPED caused a 17 car pile up. The cars before him/her didn't stop, and that PLUME of smoke would of been seen a mile away to allow that person to slow and prepare for it.
Oddly enough once you hit a straight piece of road, even if you let go of your steering wheel you will travel straight enough for a long enough period of time to probably make it past the bridge, that's with no hands and accounting for road banking for water run off.
No, god damn excuse.
The only excuse for stopping is they thought the bridge was out and did not want to drive off it into the river (like all those people did on the Sea to Sky highway when the debris torrent wiped out a bridge years ago), or else they feared someone else may have stopped and feared running over someone. I bet many of those people driving to their deaths off that bridge into the torrent were thinking the same as you...the cars in front of me didn't stop, no god damn reason for me to stop.
While I agree the smoke should have been visible from a distance, so there was plenty of time to stop and pull over, I am a little more understanding about why they may have stopped. Obviously the person made a judgement call to continue when they first saw the smoke (their first mistake). Once they decide to proceed over the bridge, they essentially were committing to it. However, you are not legally able to keep driving when visibility is zero (if the police are criticizing people for driving too fast for the conditions), clearly (no pun intended) if the visibility is zero, your speed should be zero. Once he realized the smoke was thicker than expected and they could not see anymore, they had no legal option but to stop and, as I mentioned above, they may have felt that the bridge may be out. Really, are you actually saying you would go on and drive right off a bridge? I am no lemming. I would have stopped... but then I would have stopped before reaching the bridge.