For hitchhiking from Kalamata to Tripoli , Athens : go to “Nea Eisodos” street which contacts Kalamata with Messini and a good spot may be outside the supermarket “Lidl” Sparti : go near the bus station
Greece is one of the worst countries for hitchhiking. Especially in winter/autumn time. Maybe it should be edited so people don't end up in a bad situation. Like I have, waiting 7 hours outside Thessaloniki.