If you're travelling and it's not for one of the reasons listed on the below webpage:
These Regulations impose restrictions on the occasions on which a person can leave or be outside of the place where they are living and on gatherings. They also require the closure of a number of businesses, and impose restrictions on businesses.
www.legislation.gov.uk
Then it's not legal to be travelling.
It's not necessary to specifically make 'travel' illegal because simply not being at home without reasonable excuse covers the offence.
Again - I don't agree with the regulations