I work for a tunneling contractor and we regularly cycle through the tunnels to get from site to site, far quicker than using the car in city centres.
Best one was the London water ring main, where we would cycle from Merton to Battersea through the 3m dia tunnel and have competitions to see who could do the highest wall ride.
I went down the tunnel one day to see a tyre track looping all the way round, but the Engineer in question finally admited he'd rolled ot over by hand – ha!
The Top gear feature last year where they drove the car through the tunnel was also on our Belfast Tunnel job and believe me there were a lot of bent cars dragged out of that tunnel – ha!!