Frequency and Spines

Frequent service frees transit agencies to run better, more efficient networks. Centro’s current network is designed around the lineup—a tool that facilitates transfers in when the buses don’t run very often. But there are other design tools—like the spine—that can turn that infrequent service into the high-frequency, high-quality transit system that Syracuse needs.

Riders on Munich’s spine-based network can catch any one of 7 different trains to get through the middle of town. Because so many trains serve the same stations, the next one is never more than 4 minutes away.

A spine is a string of stops all served by multiple bus lines. Anyone travelling along the spine can catch any of the different buses that serve it even though all of those buses might have different final destinations. So someone riding from Downtown to James and Lodi, for instance, can catch either the 23 or the 80 bus because both bus lines are identical as far as that person is riding.

Spines multiply service frequency. If a spine is served by four different bus lines, each of which run every 40 minutes, then the spine sees a bus every 10 minutes—that’s the difference between the kind of lackluster service that Syracuse has now and the quality service that it needs.

Centro doesn’t make much use of spines because its network is designed around the lineup. Buses from multiple lines all get to, and leave from the Hub at the same time. This facilitates transfers, but it makes spines impossible—if all of the buses serving a spine left the Hub together, they’d just show up in bunches of four every 40 minutes instead of spreading their service out to arrive every 10 minutes.

Get rid of the lineup, and a spine-based network could redefine public transportation in Syracuse. Take the service between Downtown and the Mall. The STSA identified that corridor as a good candidate for high-frequency service, and SMTC planned a BRT line for it. Buses should run up and down North Salina Street every 10 minutes all day.

Centro could offer that service with the buses it’s running now. The 16, 46, 48, 50, 84, 86, and 88 bus lines all run from Downtown up past the Mall and the RTC, but they spread their service out over multiple parallel routes. If Centro operated all of those bus lines as a spine running up North Salina, it could provide service every 10 minutes from 5 am to 1 am every single weekday.

In fact, the six ‘transit improvement corridors’ from the STSA lend themselves well to a spine-based network, with spines providing extremely frequent service up N Salina, University Hill, and Gifford St. Run these BRT lines in spines, and the city center would see service running as frequently as every five minutes.

Spines are a great way to get high-quality, high-frequency bus service. They are service multipliers, doubling or tripling service frequencies without any added cost. They could turn Centro’s existing barely adequate service into the kind of transformational public transportation that Syracuse needs.