SacRT, and many local politicians, want the Green Line to the Airport to be the next big transit project in the region. I have doubts, and have written about them before (Green Line to the Airport, Open houses on Green Line to the Airport, linking the colleges?, SacRT light rail extensions). Jarrett Walker, my favorite writer on transit, has posted Keys to Great Airport Transit, a great analysis of rail and bus transit to airports.

1. Total travel time matters, not just in-vehicle time: Not sure how the Green Line measures up, but it is indicative that the Green Line to Township 9 (the current destination) runs on an infrequent schedule (60 minutes) during a small part of the day, because it is beyond the area where most people travel. The airport would also be beyond where most people travel, so is likely to have infrequent and short hours service.
2. Combine air travelers and airport employees on the same train/bus: The Green Line might do OK on this, though light rail already suffers from the perception of higher income people (which is mostly who flies rather than takes the bus or train) that light rail is only for poor people.
3. Connect the airport to lots of places, not just downtown, by providing a total network: Since the SacRT network fails pretty badly on connectivity already, it is likely that the Green Line will suffer from the same issue.
4. Don’t interfere with the growth of other services: The Green Line is definitely a negative on this issue. The Green Line to the Airport would gobble up all the construction funds for years, as well as a large slice of operating funds. Fare recovery on the network is 23%, somewhat below average, but the extension would likely reduce this significantly. If distance-based fares (which SacRT has talked about but done no real planning towards) are implemented on the light rail system, the operating subsidy might be less, but it will still compare poorly with the rest of the system.
5. If you can afford it, go via the airport instead of terminating there: Not applicable to the Green Line because there is nothing beyond the airport except agricultural fields, and a bit further out, sprawling suburbs that would never generate ridership.

I think the right solution for airport access is frequent bus service (15 minute frequency) from downtown to the airport, from 5:00AM to 12:00 midnight, for travelers and airport employees, and less frequent service from midnight to 5:00AM, for employees. The current Yolobus 42A/42B provides infrequent (60 minute) service from 5:30AM (6:30AM on weekends) to 10:00PM. In addition, there would need to be service from eastern Sacramento/Roseville, but I’ve thought less about how that would work.

Save our infrastructure funds for more productive routes!