Public transportation works best as a network. When riders can transfer between multiple buses to access more of the city, the service is exponentially more useful than if it consisted of just a single line. And since additional service makes existing service even more useful, Centro should build out the biggest BRT network that it can as soon as it can.

To see how this works, just look at the 2 lines that SMTC proposed in the SMART1 study. 3,912 workers live within a 5 minute walk of a station on the SU-RTC line. 512 of them (13%) also work within a 5 minute walk of a station. 7559 workers live within a 5 minute walk of the Eastwood-OCC line, and 1101 of them (15%) also work along that line.

If you account for the 552 workers who live within walking distance of both lines, about 1,500 workers (14%) could use one of these two lines to get to the jobs that they work now.

But good transit doesn’t work as a series of individual lines—it’s a network. These two BRT lines will intersect at both St. Joe’s and at the Hub, so anybody who lives along either line could use those connection points to change buses and access any job that’s located along the other line.

And when you account for that network effect, it turns out 2,407 of the 10,919 workers (22%!) who live within walking distance of a planned BRT station could use the service to get to the jobs that they already have. Some people who live along the SU-RTC work along the Eastwood-OCC line and vice versa, so when the two lines operate as a network, each one is more useful to more people.

Add more lines, and those numbers will climb even higher. Run a line up South Salina and out Erie Boulevard to Shoppingtown, and 4,403 out of the 16,808 workers (26%) living within walking distance of a BRT station could commute to their current jobs by bus. Run another from Shop City to Western Lights through the North and West sides, and the number of potential bus commuters rises to 6,714 out of 23,969 workers (28%). That’s 1 out of every 10 people who work within walking distance of this 4-line BRT network.

And what’s true for commuters is true for people who ride the bus for any other reason too. Someone living just off North Salina might be able to use the SU-RTC line to get to the Mall, but they’d need to connect to the Eastwood-OCC line to get to school at OCC, or the Valley-DeWitt line to visit family in Salt Springs. More lines going more places make the network more useful to more people.

The network effect is what makes transit work. No individual line can be very useful all on its own, but any line gets more useful when it operates in tandem with another line. Every single line in a network gets more useful every time another one gets added to the network. That’s why Centro takes such pains to facilitate transfers at the Hub, and it’s why when Syracuse starts running BRT it should build out as many lines as quickly as possible.