asked the Minister of Transport if he will estimate the number of cars and goods vehicles passing the most heavily used part of the M1 motorway on an average day.

The most heavily used part of the M1 on which the Department carries out regular traffic counts is between junction 9 and 10.

Average daily flow between Junctions 9 and 10 on the M1 (1978)
Cars and taxis	…	…	53,400
Light goods vehicles	…	…	4,600
Heavy goods vehicles	…	…	15,100

Sections of the M1 nearer London, in particular between junctions 7 and 8, may have slightly higher flows but no regular counting takes place on them.