Monday, September 30, 2013

More Reflections on TOD

TOD emerges from a 'Joint Development' context, which it fell under the aegis of Redevelopment Agencies. The amount of developable land in the quarter mile radius around a transit station is small enough the become a 'project' for a redevelopment authority, rather than a planning-scale enterprise. This has both benefits and hazards. They can be prone to monopolistic situations where a single owner declines to develop. They can also be 'sterilized' by administrative, legal, or topographical complexities.

Development is not autocatalytic process--it needs something to start it. A 'landmark project' can set the tone of an area. A quality new building is a neighborhood amenity, and can catalyze a 'virtuous cycle' of public investment, rising amenity, & private redevelopment. So can a major public investment.

The primary value of any property has little to do with the property, and everything to do with the location of the property.

Ridership and Service

The relationship between ridership and service is not linear, but elastic. Ridership declines more than a proportionate cut in service would suggest, as transit relies on a 'network effect'. As service declines, ridership declines more. The opposite is true of service frequency. Doubling the frequency more than doubles the ridership. There is a lot of 'latent demand' for transit service that is never met. Transit agencies are effectively 'monopoly providers' of transit service. Not just because of their public

An effective private transport network would need to include a mandate that all operators honor each others tickets. And were fairly compensated for doing so. Because when it comes to networks, transfers are the name of the game.

Service has two components: Coverage and Frequency
Coverage: "Can I get there?"
Frequency: "How long until the next one comes?"
Fast, frequent and reliable BRT service to act as a 'trunk line', facilitating transfers. Transfers are brutal when the 'transfer penalty' is 10+ minutes on a 30 minute journey. Half headway is the typical calculation of transfer penalty. I'd say it's more like headway, because the uncertainty about bus location doubles the stress and hassle. Have you just missed the bus? Is it coming? And will it stop when it reaches my stop? The last one kills me--means I have to be constantly 'on guard', while at a TRAX station I plop down and open a book.

Grading BRT

Fare Collection
A - Free
B - Offboard
C - Onboard

A-Grade Seperated
C-BAT Lane
D-Mixed Traffic

A-Median Dedicated
B-Flush-curb/level boarding.
C-Curb & gutter
-1 for Bus Pullouts

Peak Headway
A-5 min or less
B-10 min
C-15 min

Worse Headway
A-10 min or better
B-15 min
C-20 min

Stop Spacing, Average (Difference from mean of 1/2 mile)
A - <.1
B - <.2
C - <.3

Stop Spacing, Deviation from Optimum
A- σ<=.1 miles
B- σ<=.2 miles
C- σ<=.3 miles

Have to do something about the DISTRIBUTION of stop spacing, not just 'average'. Perhaps something with standard deviations?
σ<=.2 miles

What else matters? 

Operating Hours out of 24 (buses per day? Per week?) much of ITDP only applies to developing world 'Surface Subways'

Propulsion Tech
A- Electrified
B - CNG, etc.
C- Diesel

Wheelchair boarding
-Boarding plates
-Wheelchair lift

-Stop request signals
-NextBus information (realtime passenger info)
-System Map
-Area Map
-GTFS feed
-Automatic Vehicle Information

Bike integration?

Multiple-Door Boarding

-Transit Signal Priority
-Queue Jumps

Modeling Transit Netowrks

Transit NETWORKS rather than transit LINES. Really need some transit network metrics. An index or transit networks, which covers frequency, travel time...not mode. Connections, count of nodes, that is the important thing. Do two co-linear lines count as connections? Yes, but with transfer penalty.

Need an index. Index is of what? Of the network. But I also need a 'score' for the entire network. Transportation networks use 'delay'. (Think I can use travel modeling software for this.) Two parts to it, though. The network and the TAZ. Socio-economic data is pretty easy to come by. LEHD, use the LODES, and I've got a trip-matrix.

Less frequent service makes transit journeys take longer, so it is equivalent to congestion?

BRT as streetcar replacement

Places that once had streetcar are now getting BRT. Because the areas were originally 'TOD', the urban form is a good fit for BRT.