Means of escape & access for the fire & rescue services are part of the design considerations for modern road tunnels.
For a single direction tunnel, the assumption is that drivers will stop before the fire & leave their vehicles, evacuating in the opposite direction.
It’s not a good idea to drive past the fire as smoke control systems will typically be designed to ventilate smoke in the direction of travel & protect the means of escape/firefighter access route.
Passing the fire can lead to you being trapped in hot smoke & unable to breath.
Escape routes will be available & should be signposted, or in some cases the expectation is that occupants will evacuate via the portal by which they entered the tunnel.
Bi-directional tunnels follow different engineering approaches but the basic principles remain the same.
Emergency points are usually provided & identified to enable occupants to report a fire to the infrastructure operator.
More modern tunnels usually have fire & smoke detection, incident detection, voice alarm, smoke control & fire suppression systems.
Driving past a vehicle on fire can put you, your passengers & firefighters at risk.
Drivers can be reluctant to abandon their vehicles but this is the safest approach & allows firefighters to focus on extinguishing the fire, not on rescuing you.
Once the fire is out, smoke has been ventilated & it’s safe to re-enter the tunnel then you will be allowed to collect your vehicle.