Pulling to the side when the traffic jam starts, not only when the firefighter walks up and knocks on the window.
Also, since it's a relatively time-insensitive situation (as in, tens of seconds to deal with it rather than seconds), once it identifies that it's an exceptional situation, it can have someone connect to the truck remotely.
> Pulling to the side when the traffic jam starts, not only when the firefighter walks up and knocks on the window.
And get overtaken by other drivers :) Then a lot of honking and swerving would be needed to get back in the correct lane. Also they sometimes need to back up a bit, to let a 'late' driver to move infront of them, or behind them, move to the other side, interpret what honking means to whom, etc... or drive forwards a bit, or whatever the firefighter knocking on the window tells them, speech recognition is still not perfect and interpreting abstract orders is even worse.
> it can have someone connect to the truck remotely
This is covered in TFA, and noted that one cannot rely on wireless connectivity along all highways. Certainly not immediate responses, and doubly-so when the vehicle may be in a deadzone; either a natural one or one caused by overloading the local towers (such as one might find at a remote accident with lots of other motorists) will do.
Also, since it's a relatively time-insensitive situation (as in, tens of seconds to deal with it rather than seconds), once it identifies that it's an exceptional situation, it can have someone connect to the truck remotely.