An important performance measurement for almost anything is the amount of service provided. In transit, this is reflected in ridership. More people riding public transit is generally good news for transit agencies. Ridership is measured in unlinked passenger trips. Effectively we’re talking about the number of boardings. If one person goes on a trip from A to B by first getting on Bus 1 then transferring to Bus 2, that would count as two unlinked passenger trips.
Ridership is crucial for many reasons. First, higher ridership can help transit agencies be more cost effective. 20 people riding the 8am bus is better than 5 people because the cost per rider is much lower. More importantly, many of the secondary benefits from public transit (such as traffic congestion and economic development) are dependent on the ridership. If Chicago builds a new subway line but no one rides it, there will still be the same amount of traffic along that corridor.
This past week, I explored ridership trends for all 24 cities. I was able to find the data from the National Transit Database (NTD) and the American Public Transportation Association (APTA). The oldest data I could find were from 1995.
There were a handful of cities that grabbed my attention. I’ve decided to highlight two in this post; Salt Lake City and Minneapolis.
Salt Lake City
Here we have the ridership trends for Salt Lake City. For an easier analysis, I have only included motor bus and light rail as the modes of interest. Salt Lake City introduced their LR in 1999. Ridership grew at a reasonable pace. What’s interesting is that the ridership for bus has stayed relatively constant. This is a good sign. One fear of introducing a new LR system is that it will take riders away from the bus system and will not add any new riders to the overall transit system. We can see here that overall ridership grew, and it is reasonable to say that LR contributed to that growth.
Minneapolis
In Minneapolis, we see a completely different story. When LR came on in 2004, there was some increase at first, but the line immediately reached its peak. Notice how bus ridership starts to decline with the introduction of LR. This is a case where LR does not appear to have added anything to the transit system. Now, the last two years saw great growth in LR. In the coming years, maybe this trend will continue?
Takeaways
One cannot simply look at ridership to get a complete story. Dozens of other factors are constantly at play. Population growth, changes in the amount of service provided and fare prices all impact ridership. A simple growth in ridership could mean nothing. But this serves as a good starting place. As I move forward this summer I will be looking at those other factors. What is really driving these ridership trends?