Pace, the suburban bus division of the Regional
Transportation Authority, provides fixed bus routes, dial-a-ride services,
vanpools and special events bus service throughout Chicago’s six-county
suburban region.
This service area encompasses approximately 3,446 square
miles in the counties of Cook, DuPage, Kane, Lake, McHenry and Will. Created by
reform legislation in late 1983, Pace began operating in mid-1984. It is
governed by a 12-member board of directors comprising current and former
suburban village presidents and city mayors.
The Pace service area includes some 210 communities with a
combined population of 4.5 million people. As of 2000, Pace’s annual
ridership was 38.6 million with an average weekly ridership of 135,000 people.
IBS overview
With a successful traffic signal priority project in operation and new technological advances on the horizon regarding ITS, Pace sought to develop an enhanced bus management and monitoring system that utilized some of the latest ITS advances. The application of these technologies into a system unique to Pace was dubbed the Intelligent Bus System.
The IBS generally provides for three major functions:
• Computer
Aided Dispatch—functions for control of voice and data communications
between Pace’s revenue and non-revenue vehicles and their assigned
garages/divisions which will be integrated with the existing Pace radio
communications system;
• Global
Positioning System—based automatic vehicle locations functions that are
tightly integrated with the supplied CAD functions; and
• Integration
of supplied CAD/AVL functions with Pace’s existing HASTUS fixed route
scheduling facilities and other computer systems.
All three of the above functions are based on schedule
information. With on-board computers and all connectivity in place, the IBS
automates many monitoring functions with real-time outputs, previously
unattainable. Transfer connection capability and signal priority capability are
en-hanced. Based on schedule information within the on-board computer, signal
priority can now be requested only as needed or when buses fall behind
schedule.
Many improvements are achieved with the IBS, but the
singular most noticeable advantage to passengers is traffic signal priority.
This function ensures more reliable service. Various technologies are available
to achieve signal priority such as loop detection, radio communication or
optical detection. Because the region’s political make-up is so diverse,
it is the intent of the IBS to provide a system that is compatible with up to
three transit signal priority methods.
In addition to signal priority and the AVL system, automatic
passenger counters help enhance on-time performance monitoring. A portion of
the fleet will be equipped with APC’s allowing collection of real-time
data on boarding activity and load factors.
The initial implementation of IBS on 605 buses is
anticipated in 2002 with estimated growth to 625 buses by 2014.
Cermak Road background
One of the greatest debates by users and non-users of
transit is the convenience of travel time. Unless provided with exclusive
rights-of-way, bus transit is too slow in mixed traffic—the personal
automobile is the greatest competitor. Because transit must make multiple stops
in a single trip it is, by nature, slower than auto travel.
How can this situation be combated and become more
productive?
Interestingly, numerous articles on the subject have
suggested that as much as 40% of schedule time is spent waiting at traffic
signals. Whether one believes this statistic or not, it clearly suggests that
if transit could eliminate or reduce its waiting time at traffic signals,
travel times could significantly be reduced. There also is a psychological
advantage to operating buses with signal priority. As drivers of personal
automobiles stuck in traffic observe transit operating through an intersection
(with priority) the perception of “faster mode” is enforced. Signal
priority for buses not only increases operating efficiency but also attracts
new ridership.
Given the advantage of signal priority to transit, traffic
engineers have traditionally opposed implementation suggesting that transit
signal priority would adversely affect general traffic and, particularly, cross
traffic at priority equipped intersections. In 1995, the Illinois DOT, Pace and
the Chicago Transit Authority sought to test the effectiveness of signal
priority for buses and a consultant was hired to conduct a feasibility study.
Upon completion of the feasibility study in June 1997, IDOT
in collaboration with Pace and the CTA, implemented a signal priority
demonstration in a 21⁄2-mile corridor of Cermak Road, located in the
Chicago suburbs of Berwyn, Cicero and North Riverside. Although the corridor
study includes some 20 signalized intersections, the demonstration project encompasses
15 traffic signals—only those signals through which the buses travel.
During peak periods, there are up to seven buses per hour in
each direction and four buses per hour in off-peak periods.
Upon full optimization of traffic signals in the corridor and
activation of priority equipment, running times on westbound bus service
experienced an average 15% reduction—three minutes—within the
21⁄2-mile project area. Actual running time reductions varied from 7-20%
depending on the time of day. Eastbound running times experienced an average
16% reduction, or three minutes, within the corridor with actual running time
reductions ranging from 12-19% depending on time of day. In addition to
improved running times, Pace realized a savings resulting from fewer buses needed
to operate the service and more efficient scheduling of equipment. As a result
of successful implementation of transit signal priority, Pace has reduced the
number of buses on the street without affecting service, and, more notably, the
satisfaction level of passengers has increased since signal priority was
implemented and additional ridership may be attracted.
A loop detection system approved by IDOT was chosen for this
demonstration. The system consists of a transmitter (or transponder) mounted on
each bus to place the priority request. The signal from the transmitter is
received by an in-pavement loop located at a distance of 250 ft in advance of
the intersection. An additional “check-out loop” was installed
downstream of each intersection.
It should be noted that as part of the demonstration
project, the 15 intersections within the corridor were provided with new
controllers that were fully interconnected. The signals were re-timed to
provide full progression along the corridor and this provided significant
improvements for general traffic operations.
At the same time the signal priority test was under way,
Pace developed a list of potential signal priority corridors for future
implementation. This list identified roadways within the core region with the
most congested and heavily traveled routes. These corridors lie mainly in Cook
County. While other potential corridors have been identified within the
six-county region as part of Pace’s Comprehensive Operating Plan, the
core list serves as a basis for implementation of future transit signal
priority projects.
Western Avenue corridor
Other transit signal priority initiatives are being studied
in the region. The city of Chicago and the CTA, in cooperation with the RTA, is
exploring potential for transit signal priority along a segment of Western
Avenue between 59th Street and 87th Street, within city limits. Pace is a
stakeholder in this project because it operates service on Western Avenue
between 79th and 95th Streets on Pace Route #349. Previous technologies
explored by the CTA include radio-based wireless short-range communications
with traffic signal controllers at several intersections on Martin Luther King,
Jr. Drive between 43rd and 51st Street.
Whichever system is ultimately deployed in Chicago, it is
important for Pace to maintain a regional compatibility with traffic signal
priority.
B-to-B communication
Unlike other transit systems that may exclusively depend on
a central dispatching or control center to relay information, Pace allows
operators to communicate directly with each other via radio.
The proposed IBS is intended to enhance existing bus-to-bus
communications. Pace is requesting that the IBS provide for bus-to-bus
communication without assistance from the dispatcher. This is the current
practice, allowing for bus operators to contact other buses in order to
facilitate transfer between routes. Much of Pace’s service operates at
30-60 minute frequencies. If a transfer is missed by 1-2 minutes, the passenger
could be faced with a lengthy wait for the next bus.
Thus, operators are trained to contact connecting buses by
radio of they are running behind schedule and have passengers that want to make
a transfer. While other AVL/Dispatch systems include connection protection
functionality, this requires using the on-board data terminal by both the
originating operators and the operators on the connecting bus. In many
circumstances, this will work fine. In other situations where the operator is
contacted by the passenger at the last minute, or where a bus starts to leave
before transfers are accomplished, the use of the terminal is not timely
enough.
The voice radio can be used in these circumstances. Most
current systems require operators to call the dispatchers and request that the
dispatchers facilitate the radio contact with the connecting bus. If the
dispatcher is temporarily occupied with other issues, or has several requests
to talk waiting, the transfer opportunity may be gone before voice contact
between operators is assigned.
Including the bus-to-bus voice contact in the system could
allow for quick and effective contact between buses to assist passengers
transferring. This feature also should assist in other circumstances, such as a
rider boarding the wrong bus, or assisting in vehicle trades without taking up
dispatchers’ time.
Dispatching capabilities
In order to service the large geographical area that Pace is
responsible for, a total of nine garages are operated in the region. These
garages house from 30-120 buses each. Each garage has a dispatcher responsible
for overseeing operation of buses from that garage. At present, there is no
central dispatch facility and none is currently planned.
While there would be some benefits to a central dispatch in
terms of coordination and perspective, these are not substantial. The
inter-connections between services operated by the different garages are
relatively minor. Many more connections are made with CTA service and, in some
cases, Metra commuter rail service.
Economic benefits from consolidating dispatch positions in a
centralized facility are problematic. Each garage has one dispatcher on duty
with the exception of the large garages where a second dispatcher may be added
during busy periods of the day. In addition to radio dispatching and service
restoration, the dispatchers also check in drivers for work and fill open
assignments with available operators. Thus, if the radio dispatching and
service restoration functions were centralized, manpower would still be needed
for driver check-in and related duties, yielding little or no savings.
Closing
This article has highlighted existing efforts to develop a
system of ITS-based applications for suburban bus service in northeastern
Illinois and has briefly described several demonstration projects and elements
of the IBS.
Not all elements of the IBS have been discussed. Transit
signal priority is a major element of the IBS and operationally may have the
greatest impact to service improvements on a system-wide basis. Until full
implementation, various signal demonstration projects and other individual
efforts to implement parts of an IBS will continue. These independent projects
will be included as part of the phased implementation of the overall system. TME
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