This paper introduces a speed adaptation system using
roadside-to-vehicle RF communication. The RF transmitter transmits
transmitter''s ID, speed limit, message to the drivers. The
messages include occurrence of accident, freezing road, existence
of gas station, or construction on the road, etc.
At present, drivers identify the speed limit from speed sign
board. But drivers cannot concentrate his attention continuously on
finding speed sign board, so over speed takes place
unintentionally. And one of current information medium to the
drivers is variable message sign board (VMS) showing the present
road status such as severe congestion, occurrence of accident, or
heavy rain. But due to high installation cost of VMS, insufficient
number of VMS units are installed on the road. So timely
notification of traffic accident to the following drivers is
impossible now. Our system is low cost to be installed at close
intervals on the highway.
Each RF transmitter on the roadside in linked to the central
command center by wireless system such as beeper or cellular phone
for information input. In our system, the driver who encounters any
traffic accident reports to the RF transmitter by pushing a button.
The RF transmitter then transmits the signal to the central command
center where the information is forwarded to the roadside TX one
station back, so that following drivers can get information in
time. Messages are displayed on an LCD panel as well as through
speaker. If the speed of the car exceeds the speed limit of the
road, the main controller issues alarm messages and when no action
is taken by the driver, the acceleration pedal is automatically
controlled until the speed of the car becomes below the speed
limit.