> The vehicle will wait one second before starting off when traffic lights turn green
Remember that the car has advance knowledge of when it's going to change (Audi just demonstrated that), it doesn't need to wait for it to actually change. 1 second is quicker than a human can react to the light changing and go from brake to accelerator (for the US), or select 1st and release the handbrake.
It also knows exactly when a light will go from amber to red, so knows whether it can make it through before the light changes. It takes more "chances" than a human driver would, so there would be at least 1, possibly more, less cars waiting.
> Do they work as well at night
Laser, radar and lidar don't give a rat's ass whether it's dark. Microwave sensors won't work as well in fog, but it's probably still better than a purely optical system (i.e. eyeballs). What may not work as well is lane tracking, but you may be able to combine infra-red to give it a better chance.
> noticing there’s no gap between each car in the platoon that’s large enough to let you in
The 'platoon' is under autonomous control, so it can either detect your indicator and make room, or inter-car communication triggered by your indicator tells the leader "make a hole, I need to get off here".
> Does the whole platoon move sequentially, car by car, into an adjacent lane and
> overtake the slower vehicle
Probably depends on road conditions. If there's enough lane space move the entire platoon, if not move over individually and pass when it can. The leader will need to split the platoon and hand control to the car immediately behind you, and join it back up when it catches up.
> What happens when the GPS data is unavailable
Same as with dashboard navigation units, it falls back on inertial navigation. It knows you went into a tunnel, so it's a fair bet you're on the road that goes through the tunnel, so can use vehicle speed to work out where you are.
> so far off that the car goes off the boundary of its stored map
A 64Gb card is enough to store the road maps for the whole world. The more detailed maps used by autonomous cars may be bigger I guess, so give it a 2TB hard disc.