INGENIEUR
RESULTS AND DISCUSSION
Input Data (Intersection, Approaches and Lanes)
In SIDRA Intersection data can be entered using
graphics-based input dialogues. The intersection
geometry and signal phasing style of SIDRA
Intersection directly reflects the design process.
The approaches and lanes input dialogue allows
the analyst to type in approach road names and
specify the various data which describes the basic
characteristic of an approach road (or intersection
leg), and existing lanes. Then, movement class
and lane declines are updated before the volume
of vehicles is keyed in and the data is processed
(refer to Figure 4.1).
Existing condition (Before improvement)
Level of service
The value of delay, queue journey time and speed
obtained from practical measuring data at the
site shows the level of service (LOS). In the case
study the LOS level is F and drivers experience
long delays, long travel times and low speed.
Figure 4.2 shows the existing LOS at the Bukit
Chedang T-Junction. The current situation needs
to be improved significantly in order to reduce
the volume of traffic as well as effectively control
traffic at the intersections.
Results (After improvement)
The results from the study show that the level
of service requires improvement as well and
the percentage dissimilarity before and after
improvement can be observed. Figure 4.3 shows
LOS change after improvements.
After making some improvements in traffic
light timing phase there was no significant
improvement.
Adjusting cycle time of the intersection
according to the volume of traffic flow showed no
significant improvement.
The solution to significantly improve LOS at
the junctions was changes in road alignment, with
the addition of a slip lane to reduce the volume
of congestion and long queues, and adding new
lanes to increase the capacity of intersection.
After an improvement/upgrading the results
are shown in Figure 4.3.
Figure 4.1: Lane Description and updated vehicle volumes
6
46
VOL
2018
VOL 74
55 APRIL-JUNE
JUNE 2013