What we’ll cover
• Types of transit networks and their attributes
• Transit networks and placemaking• Interaction between roadway
networks and transit networks
What’s a transit network?
Transit Network: the spatial configurationof the individual lines of a transit system
What’s a sustainable transit network?
1. Enabling: people can travel without depending on private vehicles
2. Efficient: consumes least amount of resources for what you get
3. Fast: allows for timely travel4. Affordable: can be maintained in all
economic climates
Transit Network Typologies
Radial Grid Hub and SpokeAmorphous
Transit Network Typologies
Amorphous Networks
Amorphous Networks
Amorphous Networks
• Confusing• Difficult to coordinate transfers• Not a network that you’d ordinarily
design• May be all that can be done on
older street patterns
Radial Networks
Radial Networks
Radial Networks
Radial Networks
Radial Networks
Radial Networks
• Ideal for serving one central activity center
• Inflexible to changes in activity locations• Access any point on network with a
single transfer • Can require out-of-direction travel• Poor continuity on grid street systems
Grid Networks
Grid Networks
Spacing: 0.5 mile or less
Grid Networks
¼ mile walk
Frequency: 12 minutes or less
Grid Networks
Grid Networks
• Ideal for area wide coverage• Needs high density to justify frequent
service• Best suited to grid street networks• Greater likelihood of transfers• Not convenient in low-density areas
Hub and Spoke Networks
Hub and Spoke Networks
Hub and Spoke Networks
Hub and Spoke Networks
5%5%
CBD
95%95%
Hub and Spoke Networks
• Ideal for serving many activity centers• Less frequent service can still be
attractive• Relatively economical to operate• Timed transfers are essential• Transfer facilities should be of high
quality
Enabling
Efficient
Fast
Affordable
to center
elsewhere
Transit Network Typologies
local bus
rapid transit
commuter rail
Transit Networks and Placemaking
Transit Networks and Placemaking
Radial Grid Hub and SpokeAmorphous
bus line
rail line
Transit Networks and Placemaking
CBD
Transit Networks and Placemaking
TOD?
4 localities accessed directly
CBD
Transit Networks and Placemaking
TOD?
7 localities accessed directly
CBD
Roadway vs. Transit Networks
Most forms of transit – but not all –are dependent on the roadway network
Roadway vs. Transit Networks
Surface transit needs roadways to access potential riders
Roadway vs. Transit Networks
Potential riders need streets and sidewalks to access transit
Roadway vs. Transit Networks
Connectivity and Density of the roadway network are critical to transit
Network Connectivity
Network Connectivity
Network Connectivity
Network Connectivity
Network Connectivity
Network Density
1/4 mile1/4 mile
Network Density
Network Density
1/2 mile1/2 mile
Conclusions
• Networks are unseen; understand the big picture before tinkering with the details
• Sustainable transit networks must be enabling, efficient, fast, and affordable
• To serve one principle activity node: - Radial transit network is best
• To serve many dispersed activity nodes:
Conclusions
• To serve one principle activity node: - Radial transit network is best
• To serve many dispersed activity nodes:– Grid: frequent transit service in dense
areas with grid street system– Hub-and-Spoke: for most other
situations
Conclusions
• Connectivity: connected streets permit transit to reach riders and riders to reach transit
• Density: streets suitable for transit service should be spaced every half mile to ensure an easy walk to transit
Conclusions
• Intense activities should be located near a transit network’s points of confluence
Conclusions