MILJ OCH PLANLGGNINGSBYRN

1
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
SYVARI A SIGNAL CONTROL STRATEGY for
implementing public transport priorities
Matti Salonen - City of Turku Next-meeting
21.-22.4.2009
2
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
SYVARI is based on the flexible stage ring1)
control which is commonly used in isolated
intersections
gt Permissions to change to green and inhibitions
on permissions are given by the stage ring
1) Change from one stage to another happens
movement by movement (phase by phase)
3
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
In SYVARI the proceeding of the stage ring is
modified by the cycle counter functions
(event/action tables) gt The stages are
synchronized with the cycle time
SYVARI synchronized stage ring
4
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
Movements need parallel maximum time counters to
realize priority functions
1) One for enabling gap extensions in order to
realize so-called guaranteed greens for phases
(basic max time counter)
2) Another for enabling gap extensions when green
will end according to the sychronization
(synchronization max time counter)
3) And the 3th for enabling bus priority
extensions (priority max time counter)
5
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
The cycle counter carries out the synchronization
by
6
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
Advantages of this kind of synchronization
1) The stage ring control works like a normal
fixed cycle control when any priority call occurs
2) When the control is out of synchronization
after a priority, the synchronization pulses will
help the stage ring back to synchronization as
soon as one of the green periods meets its
synchronization
3) Synchronization pulses cant cause
malfunctions in any case even if the stage ring
is totally out of synchronization gt
synchronization sets no limits on priority
functions
7
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
What kind of priorities can be realized by SYVARI
8
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
How does SYVARI realize priority functions?
1) Early green
During red indication the approaching bus puts
into practice a function, which sets
synchronization max time counters to zero for
all its conflicting movements
A priority demand for a left turning bus from
west
9
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
How does SYVARI realize priority functions?
2) Green extension
Always when a movement changes to green, its
priority max time counter is loaded with a big
enough time value. The value must be at least
synchro max time driving time from the priority
check-in detector to the stop line.
A bus passing over the priority check-in detector
during green indication, can get an extension
time using the priority max time and drive
through the intersection facing green.
10
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
How does SYVARI realize priority functions?
3) Extra green
Extra greens are put into practice simply by
inserting in the stage ring all needed extra
greens for movements.
Extra greens appear only if the movement has a
priority demand. Without the priority demand they
are skipped.
11
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
How does SYVARI realize priority functions?
12
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
One instance of control using SYVARI
13
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
Advantages of SYVARI

• Independent from suppliers. Programmable to
  Nordic controllers e.g. ITC-2, EC-1, EC-2 (?),
  C800V.

• Easy to design and program

• Works reliably

• Prioritizes public transport effectively

14
MILJÖ- OCH PLANLÄGGNINGSBYRÅN
Thank You For Your Attention !