How Much Does Congestion Cost Transit Agencies?
SounderBruce (Flickr)
In 2015, as SDOT began selecting Metro bus routes to improve with Prop 1 funds, much of the first round of funds went not toward frequency or speed, but to 'schedule reliability'. Basically, congestion was so bad and variability so high that one of the first priorities was simply to pad the schedule to adapt to worsening realities. Later that year in September, facing ever-increasing delays on its Snohomish County commuter services, Community Transit threw "the last $2m [they] could find" to pad their commuter schedules for reliability.
It's important to note that funds used for schedule padding amount to an indirect subsidy of our single-occupant vehicle culture. While schedule padding can reduce total delay as buses have more chances to recover, padding doesn't make anyone's trip faster. It reinforces the perceived right of open vehicular access, increases the cost of each bus trip, reduces all ridership/performance metrics, and downshifts rider expectations into a newer, slower baseline.
Directly quantifying the costs of this congestion is very difficult, but some approximations can be made. Metro has said that its buses are only moving 54% of their run time. 28% is taken up by stop/dwell time and 18% is consumed by traffic delay. Compare this to Link light rail, which is moving 80% of the time, stopped 15% of the time, and delayed up to 5% by (temporary) bus/rail conflict.
In 2015, Metro provided 3.7 million service hours. If 18% of those hours were consumed by traffic, and assuming a conservative $150 per service hour, we can infer that our car habits cost Metro roughly $100m per year in direct service costs. This would be roughly 10% of Metro's annual budget, imposed by drivers, borne by transit agencies and taxpayers. It's money lit on fire while we all sit in gridlock, all of us paying more for lesser service. So when we talk about the costs of transit, it'd be helpful to remember the unnecessary costs we already incur, and how transit priority (and enforcement) can often pay for themselves. We shouldn't be paying to absorb inefficiencies, we should be paying to fix them.