Table Of Contents - Chicago Transit Authority

CTA Express Airport Train Service Business Plan
standpoint, it would allow the dedicated Express cars to be phased into service alongside the Dedicated
Service fleet (though this could be done under most any transition scenario).
Regarding the phase-in of the dedicated Express cars, it is possible that once the prototypes have been
accepted, these cars could be introduced to the peak period services to/from O’Hare, with successive
deliveries being assigned to other trips to the point that the transition to full operation with the new cars
is accomplished.
6.1.3 Key Assumptions
Adherence to existing CTA operating practices with regard to, among others, layover times, use of dropback
train operators, etc., were basic factors considered in the development of the operating plan. In
addition, current union agreements were reflected in the staffing plan. It is possible that with contract
operations, some aspects of this situation might change.
Minimum desirable headways between future Express Service trains and existing demands for train
service on the Blue, Orange, and Red Lines were a major concern as the schedule was developed. While
the assignment did not include simulation of operations, it quickly became apparent that manual analysis
of peak period operations for both the shared Blue Line and dedicated express alignment operations were
essential in determining the workability of the proposed operations. These analyses could only be done
for the peak-of-the-peak, but they showed the extent of potential delays to both the express and local
trains, as leader trains were caught and then overtaken. The results of these exercises demonstrated the
need to ultimately conduct computer-based simulations of the intermixed operations through the State
Street Subway and on the south side elevated in particular.
6.1.4 Operating Complexities
A number of complexities exist that could effect the operation of the airport train service. These risks
include:
• Travel time and headway - Short dwell and layover times for peak period Express Service trains may
limit operational flexibility.
• Delays to local trains - During peak periods, Express Service train journeys to/from O’Hare may
regularly take up to five minutes longer than during non-peak periods on the Blue Line Elevated
alignment.
• Delays to Express trains - The manual operations analyses indicated that the peak period Express
Service trains on the Blue Line Elevated alignment may actually take greater delay than they cause to
local trains. This is due to having to run slow after catching the leading train, waiting for
signals/switches once the local is in the clear, etc.
• Increased demand for local CTA services - Systemwide, rail ridership has been increasing steadily for
more than ten years. The O’Hare Branch of the Blue Line, the Red Line, and the Orange Line have
all been experiencing ridership growth, making peak period track space a more limited resource.
• Acceptability of contract-operations by unionized CTA employees – CTA’s current collective bargaining
agreement with Amalgamated Transit Union Local 308 prohibits the outsourcing of train operations,
repair, and switching.
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