Beginning the Dialogue - Report on SGR - Federal Transit ...

Core Capacity
n Higher Capacity Cars: Several strategies exist
to increase <strong>the</strong> capacity of vehicles. Some of
<strong>the</strong>se, such as favoring more standee room over
seats, need to be carefully considered against
<strong>the</strong> grantee’s standards of comfort and <strong>the</strong>
service quality goals of <strong>the</strong> system.
r STATION CAPACITY
Station capacity will
impact, or be impacted
by, many of <strong>the</strong> o<strong>the</strong>r
core capacity elements
discussed above. Any
changes that increase
<strong>the</strong> density of
passengers using <strong>the</strong>
station, particularly
platform volumes, will have to take into consideration
<strong>the</strong> basic design parameters for <strong>the</strong> station, including
passenger flow, ingress and egress, emergency
evacuation requirements, fare collection, and HVAC
loadings. Aside from basic life safety and code
requirements, <strong>the</strong> primary core capacity issue with
stations is dwell time to offload arriving passengers
and board departing passengers, which quite often is
<strong>the</strong> controlling limitation on core line capacity.
n Vehicle Design Impacts on Capacity: Systems
using a step-up platform can reduce dwell time
by converting to level boarding platforms, which
may require new vehicles. Systems that must
accommodate boarding and alighting at street
level can adopt low-flow designs that match curb
height platforms for level boarding. Additional or
double-width doors and revised seating/standing
interior arrangements can improve <strong>the</strong> flow of
boarding and alighting and reduce dwell time.
n Platform Crowding and Circulation: Any
strategies that increase <strong>the</strong> frequency of trains or
passenger capacity of trains can increase <strong>the</strong>
density of passengers on <strong>the</strong> platforms, with
potential crowding and restrictions on flow, thus
increasing dwell times.
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n Modification of Station Tracks and Platforms:
Major modification of tracks or platforms at
stations can be costly and disruptive, but where
feasible <strong>the</strong>y can reduce or eliminate dwell time
constraints on core capacity at critical stations.
n Station Access: To effectively make use of <strong>the</strong>
maximum core passenger carrying capacity of
<strong>the</strong> system an equivalent number of passengers
must be able to access <strong>the</strong> system. Depending
on <strong>the</strong> nature of <strong>the</strong> immediate station area as
well as its catchment area, access capacity
enhancements to consider include feeder bus
schedules, parking, pedestrian/bicycle access,
and traffic controls.
r SUPPORT CAPACITY
Some capacity enhancements may require
improvements or modifications to support
infrastructure.
n Traction Power Systems: The capacity of <strong>the</strong>
traction power system to accommodate longer
trains and shorter headways ei<strong>the</strong>r alone or in
combination must be considered.
n Shops and Yards: Longer or more frequent
trains will increase fleet demands on shops and
storage yards.
r OTHER STRATEGIES
Because <strong>the</strong> usage of a transit system is not evenly
distributed throughout <strong>the</strong> day or by location across
<strong>the</strong> system, core capacity is typically reached during
peak periods of demand or at choke points and
locations of maximum loading on <strong>the</strong> system.
Techniques to redistribute <strong>the</strong> demand, or <strong>the</strong> growth
in demand, by time of day or by location of excess
capacity, while not directly under <strong>the</strong> control of <strong>the</strong>
transit operator, should be explored as a matter of
public policy to maximize <strong>the</strong> capacity of <strong>the</strong> system
for moving people.
n Staggered Work Hours: Policies of staggering
<strong>the</strong> start and finish times of workplaces can
reduce peak demand and make more use of