I have seen this a bit, but it was repeated on BBC TV last night, and 2nd part tonight. A fair bit of interesting News Reel film of planning and building the first motorwaus and bridges. Near the start was a scene of a traffic jam, and just visible near a bus at the back was a red Isetta. Another shot from a vehicle on a motorway and passing by on the other side of the road might have been a Scootacar, but very brief, and I was on the phone.
Anyway, quite interesting programme, lots of nice old vehicles to see, look out for it on i-player.