Suggestions were put forward to lower the speed limit on Portsmouth’s motorway to reduce snarl-ups.
The city council put forward proposals to build two slips roads off the M275 into Tipner.
Government rules meant the motorway’s speed limit had to be cut from 70mph to 50mph.
The new roads were being proposed to get multi-million pound development plans off the ground for the Tipner Lake.
An AA spokesman said speed reductions on similar motorways had shown traffic flows became much smoother, quicker and safer.
He said: ‘There is a tendency to have less bunching up which is caused when traffic moving at fast speeds has to brake quickly and so traffic can flow much more smoothly.’
Assistant city planning officer Ron Tate said: ‘Reducing the speed will increase the capacity because the amount of distance between cars travelling at a slower speed is reduced.
‘The optimum speed for the motorway is between 50 and 60mph and bringing the limit down should get more cars on the road.’