ABSTRACT

Unfortunately, many  public transport  services in Lisbon get caught
in traffic  and  earn  a  reputation  for poor  reliability.  Public
transport  performance  can be  improved by  better  controlling and
managing traffic generally. Systemas to locate, identify and monitor
vehicles  will  become  increasingly  reliable  through  the  use of
information and telecommunication technologies, especially satellite
navigation systems.

We have conducted  field trials in  September 2002,  at peack times.
We measured  the travel speed  of a bus, in a  fixed route  (Cais do
Sodré/Campo  Grande),  and  correlated  it with  the  in-car  volume
coming into  Avenida Joaquim António  de Aguiar. In the same period,
in February 2003,  we repeated the  experience  but  controlling the
in-car volume thorugh traffic lights. At peak times, the flexibility
of the  actuated  controller, with  the aid  of  fictitious  vehicle
detectors, is capable  of varying intervals within the cycle as well
as the in-car volume and providing benefits in bus travel speed were
possible through a feed-back real  time co-operative control between
urban  traffic  control  (GERTRUDE)  and  Public  Transport  vehicle
location (SAEIP) systems.

At long term we suggest the  implementation of an integrated system.
By doing that, the in-car volume will be reduced. This effect leads,
also, to an increased  commercial speed of the  urban bus company in
the same way as it was proposed in our experience.


KEYWORDS: Traffic control,  public transports, optimizations  of the
          commercial  travel  speed,  real time  feed-back  control,
          in-car volume, integrated systems.