You can't do it without the employers. Contrast the chart above to the charts in the latest UW Seattle U-PASS Annual Report (covering 13000 employees as well as students) over the same period: http://www.washington.edu/facilities/transportation/commuterservices/upass/reports One really interesting part of the approach is that the SOV parking permit is the U-PASS. In other words, even if you plan to drive alone and park, your permit to do so includes a "complimentary" transit pass. Imagine if you needed a similar "SmartPass" to use SmartPark in Portland.