Traveling from Siena to Assisi - Don’t want to spend 4 hours on a bus

Since the post has been up for awhile with no response....

I haven't used them myself but have seen enough positive forum recommendations for mydaytrip.com to throw the option out there. A quick look at cost for 4 people + luggage, departing Siena at 8:00 AM on June 9 (just guessed on the date per your previous itinerary post) turned up a cost of 389 euros. Arrival time in Assisi would be abt. 9:39 AM. Yes, it's expensive as it's likely a round trip for the driver.

https://mydaytrip.com/configurator?adults=4&children=0&currency=0&departureAt=1717920000000&isOtherDirection=true&luggage=4&passengers=4&routeId=93eb6674-ef32-4a0a-85e3-e35fda15cbd7&vehicles=1

Regarding that previous itinerary, there were some suggestions to skip Assisi as the Florence+Siena+Assisi piece was more overloaded/rushed than most of us thought was good. Did you rework that itinerary at all based on that discussion?

Rent a car and keep it in Assisi. It will be useful to have in Umbria to visit other towns besides Assisi (Gubbio, Spello, Spoleto, Anghiari, etc.).
Any other option, if you don’t like the infrequent Flixbus, will be “at least” 4 hours.

Problem is, unless the OP has revised this itinerary, they don't have time for Gubbio, Spello, Spoleto, Anghiari, etc. They were only planning on Assisi for one night, coming from Siena and moving on to Rome the next day.

https://community.ricksteves.com/travel-forum/italy/does-this-italian-itinerary-look-feasible-i-appreciate-any-and-all-suggetions

Thanks everyone! We may have to rethink the itinerary and expand our time in Florence and consider dropping Assisi until next time. If we do go to Assisi, paying the high price for a private driver is probably the path we would choose. .