For those who need to get from Avignon TGV station to Avignon town station and vice versa, or into Avignon itself, there’s a shuttle bus/navette.
It runs every 20 minutes and takes 10-15 minutes, depending on traffic; tickets cost €1.20 per person from the driver, who can give change.
Buses run from the front of the TGV station, where general parking is found (the back is where car rentals are situated).
The stop in town is just inside the city walls through the gate opposite the railway station, in front of the Post Office.
From the bus stop it’s an easy walk down the Cours Jean Jaurès, past the tourist office, which is a source of much useful information. From there it's a short walk straight along Rue de la Republique to the Place de L’Horloge, with the Palais des Papes just beyond.
Here’s a link to the tourist office map showing the main tourist area of Avignon. It can also be downloaded with other useful info from the site: