The motorway network is a big place. What are you looking for?
Roads.org.uk's Motorway Database contains pages for about 2,000 individual locations. A location can be a junction, service area, bridge, tunnel or any other feature shown on a route's exit list. You can search through all of them here.
To begin, open up the Filters box and begin selecting the options you want. For example, you could look for all the restricted-access junctions on the M6, or all the locations on the A406 that have traffic signals, or all the Roundabout Interchanges with a service area attached to them. It's up to you, and the possibilities are endless.