"Nightjar" wrote in message
...

I have read that rigid tow bars are, however, a requirement when towing on
a motorway, but have not found the relevant legislation.

There is a minimum speed limit on motorways..
there is a maximum of 4.5 m of rope allowed..
you can't reach the minimum speed limit without being done for dangerous
driving with only 4.5 m of spacing.

You need about 1 second of reaction time before you can start braking, this
would equate to less than 15 (22 ft/sec) mph with the 4.5 m spacing.
Then there is the problem of actually slowing down.

As i see it towing with a rope is just too slow to go any distance.