This excellent study prepared by Wilbur Smith Associates for the MWAA Board of Directors assesses the need for increases in Dulles Toll Road (DTR) fares to meet projected debt servicing obligations for the DTR. It also addresses their impact on DTR traffic and looks at alternative scenarios (sensitivity testing) and their impact on traffic and revenues--and much more.
The 2009 study is based on earlier cost estimates for Phase II of the Silver Line requiring $489 million in debt service payments in 2047. In October 2010, MWAA updated its projected DTR revenue needs to reflect the new cost estimate for Phase II--$3.8 billion vs. $2.5 billion earlier. According to MWAA's financial presentation, that would mean MWAA would have to collect more than $800 million in 2047, requiring fares to jump substantially from the $11.25 projected in this report. (At three percent inflation for the next 37 years, that $11.25 toll in 2047 is roughly equal to a $3.70 toll in 2010 dollars--about 85% more than DTR users are currently paying.) At the moment, MWAA is looking at alternative sites for the Dulles International Airport station location that could shave from $300-$600 million of the current $3.8 billion estimate for Phase II construction.
This Wilbur Smith study had been posted at the MWAA website, but has been deleted, probably because the revenue targets are no longer valid given the increased estimated cost of Phase II. Still, it is a good place to start in understanding the role DTR tolls may play in paying for the Silver Line. According to the compact among the various parties to the Silver Line construction agreement, MWAA--primarily through DTR tolls--will pay 57% of the total cost of the effort.
Note: I am working on a revised estimate for fares and DTR traffic in 2047 that I will publish soon. If the additional funding needs are met exclusively by fares, it will lead to a major increase in fares above the baseline $11.25 and see a substantial reduction in traffic, despite population growth in both Loudoun and Fairfax County that might use the DTR.
Wilbur Smith traffic_study_2009