Pforzheim is a medium size town in Baden-Württemberg, Germany on the northern edge of the Black Forest between Stuttgart and Karlsruhe on the traffic connections between those bigger cities. The risk of traffic jams on this part of the near motorway 8 (Autobahn 8, A 8) is among the highest of whole Germany. To relax this situation there is road constructions taking place and adding to the problem at the moment.
To travel eastwards use the on-ramp Pforzheim Ost or Pforzheim Süd or go to the service area Pforzheim that is located near the on-ramp Pforzheim Ost or rather the crossroads with national road 10 (B 10) before Niefern. Those places are some kilometres away from the town centre and it may be worth to hitchhike (the B 10) or take a bus. Buses of route 1 of the city bus service in direction Eutingen go that direction.
For westbound travels use the motorway entrance Pforzheim West. It is located on the Wilferdinger Höhe, a big industrial area in the northwest of the city. Busses of route 6 in direction “Lange Grund” go up there. The national road 10 (“B 10”, that also goes to Karlsruhe in the end) runs all the way through the length of the Wilferdinger Höhe; shortly after the towns end in the west to the right there is the on-ramp. Shortly before there is a fuel station (“Jet”) and a fast food restaurant (“Burger King”). There you can stand next to the street with a sign or with your thumb out or ask drivers at the fuel station or restaurant. Normally it's no problem to get a ride to Karlsruhe; a big part of the traffic to Karlsruhe takes that route.
To the south the motorway network runs on both sides around the Black Forest. Depending on whether your destination is east or west of the Black Forest you either start to the east or the west from Pforzheim: In the west near Karlsruhe the motorway 5 goes off to the south, being a good option for Freiburg, Basel, Switzerland and France; in the east the A 81 goes south towards the Bodensee. Therefore the recommended places to try are the same as either those for going east or west.
To go up north it is advisable to go over the A 5 that passes Karlsruhe and later joins the A 7, because normally it has more traffic than the A 7 and is easier to reach. You can also accept all the offers here that only take you to Karlsruhe; as long as you don't miss the right exit you are as good off on the northwards hitching place in Karlsruhe, that is going to be at least as good as here.