The are 9 different ways across 3 unique modes of transportation to help you travel from Sacramento to Petaluma. The fastest way out of Sacramento towards Vallejo is by bus, as it is the quickest to the Petaluma area. This doesn't necessarily take into consideration traffic or weather - so these may impact some of your decision making. It's common to find tickets for as low as $19. Amtrak operates from Sacramento to Petaluma, so you book your trip with them! Book as soon as you can, as there may be limited availability.
The trip to Petaluma is an excellent trip for the day or a nice trip for the weekend from Sacramento. The cheapest way to get from Sacramento to Petaluma is $19 and the quickest way takes just 2 hours with the bus. The earlier you can book your trip to Petaluma, the better.
While buses have recently gotten bad coverage because of cleanliness of bus stations or winter time accidents, they are can be very convenient for travel. The best part about traveling by bus to Petaluma is that it can be very cheap. That's because they usually have basic accomodations - WiFi and a restroom. Some of the Sacramento/Petaluma buses' coverage has been overstated. The real thing to consider when taking a bus from Sacramento is to consider the time of travel and the density of the cities that you're traveling to. If you are traveling by bus between Sacramento CA and Petaluma during high traffic times, you can expect to have your trip altered significantly due to traffic. Further, if you are traveling during winter, the bus schedule might be thrown off due to inclimate winter weather. Be sure to plan accordingly!
The plus side of taking the train from Sacramento to Petaluma? The accomodations, scenery, and lack of Petaluma traffic can usually be on point. Moreover, you can usually expect your average concessions - such as food and drinks. Most trains have WiFi these days as well. The worst part about trains are the price. While the train to Petaluma is often cheaper than flying, they are generally more expensive than buses. Train prices are usually set and do not vary as much as bus prices or flights or so the likelihood of finding discounts is pretty rare.