I just got an email about the WA-509 completion project just south of SeaTac airport because I have a Good to Go Pass. The total budget comes out to $2.83 billion for just over 2 miles of freeway, so a cost of a little over $1 billion per mile.
The SR-509 at peak capacity will carry around 1750 passengers per hour.
Sound Transit 3 was a $53.85 billion budget. $31 billion is being spent to expand Link Light Rail by 62 miles, so a cost of around $0.5 billion per mile. Already the Link Light Rail expansion is half the cost of the SR-509 completion project.
Link can carry around 19,o00 passengers per hour.
| Project | Cost | Passengers per hour | Miles | Cost per mile | Cost per mile per passengers per hour |
| SR-509 | $ 2,830,000,000.00 | 1750 | 2 | $ 1,415,000,000.00 | $ 808,571.43 |
| Link Light Rail | $ 31,000,000,000.00 | 19000 | 62 | $ 500,000,000.00 | $ 26,315.79 |
| Second Ave Subway | $ 10,450,000,000.00 | 60000 | 3.3 | $ 3,166,666,666.67 | $ 52,777.78 |
The math for highway expansion is not good!
Even compared to the Second Ave Subway expansion, it comes far closer to the cost of Link Light Rail in the cost per mile per passengers per hour than it does to the little-known SR-509 expansion!
This is a continuation of a theme I wrote about exploring the discussion about a new transit tunnel to New Jersey in 2022.
Even looking at the most expensive transit projects in the country, nothing comes close to the expense per passenger of highway expansion. It is hard to justify such costs of any highway expansion given their low capacity.
It shows we have the money to spend on world-class transit. We just choose not to.
Hypothetical corner
Let’s say that instead of making Link as a light rail system, based on these numbers, they doubled the budget to $62 billion in order to turn Link into a heavy rail system, tripling the capacity of the system.
- Cost: $62 billion
- Passengers per hour: 48,000
- Miles: 62
- Cost per mile: $1,000,000,000
- Cost per mile per passengers per hour: $20,833
Yeah. This is with a conservative number of passengers per hour.
No further comment.
References:
https://wsdot.wa.gov/construction-planning/search-projects/sr-509-completion-project
https://www.soundtransit.org/sites/default/files/project-documents/st3-system-plan-2016.pdf