Principle 5: Synergy

A connective and frequent network core exists due to the interdependency of each and every individual route. Thus, node placement is very critical as without it, routes can’t really connect to each other.

Public transport node (station or stop) placement decision greatly affect land uses across more than one public transport corridor, and thus should never be taken without due diligence. Trade-offs arise between efficient transfer opportunity to wider, more established areas, and direct access to new, developable lands.

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Stop placement nearest to multiple pedestrian crossroads generate wider effective catchment area (ped-shed)

Node (stop or station) placement requires thorough cost-benefit comparison between regional and local land use priorities, as it is often a zero-sum proposition.

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Regional-local context should determine transfer node placement

Transfer layout

Multimodal and multi-route public transport integration totally hinges on transfer node placement and layout. Surface transit (e.g. bus, tram) alignment can’t deviate much from present street right-of-ways. Thus all modes of public transport (including rapid transit with dedicated infra such as LRT/MRT) must consider street intersections as transfer nodes, not only due to the need to reduce walking time, but also due to the resulting network simplicity. Far-side bus/tram stop placement after intersection avoids traffic queue, and works best with priority signal.

Route and modal integration is not to be confused with fare gate integration. Multi-route and multimodal integration does not necessarily require fare gate integration (especially for surface transit), as contactless card technology allows transferring passengers to validate their tickets without incurring transfer penalties when passing thru multiple fare validation zones.

Platform - Four Way Interchange v2

Example of interchange layout for continuous east-west, continuous north-south and terminating lines

Simplifying complexity

Multimodal transfer is not as complex as it sounds, and even works on highway-to-arterial interchanges with signalized junctions.

Express and Collector Highway System can also be applied to highway buses; express service skips interchange bottlenecks and interfaces with local service at stops located in-between highway exits.

Platform - Highway to Arterial Interchange

Example of ample pedestrian-friendly interchange opportunities among horizontal Express-Collector highway lines and vertical Rapid Transit lines

Cross-platform transfers

Cross-platform transfer, which drastically cuts time it takes to walk between platforms, typically involves a parallel interchange between two subway routes with similar trip directional patterns.

A typical cross-platform subway transfer requires island platform pairing of similar-direction routes (e.g. inbound-inbound and outbound-outbound transfers). A sequence of two cross-platform stations (similar-direction transfer for the first and counter-direction for the second) on two parallel routes allow multidirectional transfers. This results in route redundancy along the parallel stretch, unless if it serves a reasonably high network-wide level of trip attraction density and ridership proportion (e.g. downtown).

Transfer Lionel-Groulx

Sketch exemplifying similar-direction cross-platform interchange in Montreal, Canada

Cross-platform transfer can also work for two terminating surface transit routes of opposing directions (e.g. bus-to-tram).

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Example of terminus with cross-platform transfer

Fare structure

Although fare integration does not necessarily requires physical intermodal transfer integration, the choice of fare structure affects the way public transport networks are designed across the globe. Flat-based fare structure is suitable for small towns with homogenous trip characteristics, and zonal-based alternative is effective for urban regions with topographically-bounded trip patterns.

More equitable distance and time-based structures are made possible via modern cashless cards. The former is apt for modes with dedicated right-of-ways (MRT, LRT, BRT). For surface modes (bus, trams), flat and time-based structure reduces dwell time at stops. All-door bus boarding, which eliminates both entry and exit delays, is recommended for high ridership routes, as travel time savings from reduced dwell times typically exceed fare evasion costs. Proof-of-payment (or honour-based) system with random fare checks is popular for gateless tram/light rail networks in many ‘livable cities’ due to adaptability of open platforms in tight, walkable urban environments.

Flat-Based

Pros: Higher surface vehicle efficiency (due to shorter dwell times as there’s no need to ‘tap out’)
Cons: Fare distortion for network and routes with wide range of commuting distances

Zonal-Based

Pros: Topographical urban growth barriers such as rivers and greenbelts form perfect zonal boundaries, as inter-zonal trips have to pass limited amount of chokepoints (e.g. bridges)
Cons: Fare distortion for cities with porous, multi-directional and unrestricted travel demand between adjacent zonal edges

Distance-Based

Pros: Pay-as-you-use promotes fare pricing equity
Cons: Lower surface vehicle efficiency (due to exit fare validation that prolongs vehicle dwell times)

Time-Bound

Pros: Higher surface vehicle efficiency. Promotes trip chaining behaviour, which encourages overall system ridership. Promotes seamless fare integration without the need of  costly physical integration of fare validation gates/turnstiles
Cons: Fare distortion for routes with restricted trip chaining needs

Network-oriented fare

A true network synergy requires a similarly integrated fair strategy, which eliminates transfer penalty for intermodal and inter-route trips. This necessitates formulating the fare structure based on Base Fare (also known as Block or Flag Rate) and Variable Fare calculations.

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Transfer penalty occurs when multiple-leg trip results in disproportionately higher trip fare than single-leg trip

A flat one-size-fits-all approach, as practiced by many North American transit agencies (cum operators) promotes inter-modality at the expense of trip fare distortion (e.g. 1km bus trip costs as much as 20km bus-rail trip). A variable pay-as-you-use approach used by many private urban rail operators promotes fare equity at the expense of inter-modality (rail-deprived areas pay more due to bus-rail transfer penalty). A hybrid approach should work to balance inter-modality and equity goals.

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Hybrid fare setting may suit public transport network that seeks to achieve equitable and simple fare table while reducing vehicle dwell times