Changes

Second opinion : you can walk to the entrance of the "périphérique" (ring road) at Pont Jumeaux as well (10mns walk from metro Canal du Midi), there are 2 traffic lights there. Easy to go there (plus standing at the péage might be forbidden), nice spot, but took me like 1 hour to get a ride, both times.

Take metro line B to stop Borderouge, then change bus 40 or 73 or walk to stop Atlanta. Just walk along the Route d'Albi to the road sign post before the road splits and ramps onto A62 and hitch with a sign. The passing traffic goes to Albi via D888 or A68.