First of all, sorry for my english.
The fire fighters needs other way to go to the emergency, not only the firetruck, maybe if the utility van would be implemented to attend little fire on open placed to be placate with fire extinguisher, this would make more dynamic this job.
The firefighter can take his fire extinguisher (with endless charge) from the fire station and if he take the utility van, he only can go to this "less dangerous" missions (cause he can't go to extinguish fire of the roofs).
Otherwise, can create other missions with fire on many places in a open space, but no on roofs, or make that firefighter can go on buildings interiors to attend the fire with his extinguisher.