Spring
2005
Md. Al –
Amin Sarker, Md. Moinul Hossain
Every
year millions of dollars are lost in the global economy due to traffic
congestion. Long hours spent on congested roadways are draining away valuable
time, energy and money from the economy. Overcrowding of motorways represents
the greatest bottleneck in raising the economy’s productivity, hampering it
from further potential growth. Furthermore, additional social costs in term of
environmental pollution as well as medical expenses due to traffic congestion
related symptom, such as higher stress level experience by commuters, are
depleting the limited resources available to our society. The
above discussion clearly indicates that delay should be reduced to increase
productivity and to minimize environmental pollution. the most economic way of
this delay reduction is to redesign the signal timing because this design is not
associated with spending money as well as consuming longer time. Only
readjustment of signal timing is sufficient for this purpose. Hence, to optimize
the signal timing for reducing delays has been taken as the main objective of
this study. An intersection has been chosen to achieve the goal of this study.
this selected intersection comprises Mirpur road, Manik mia Avenue & Farm
gate road with 9 movements. This
study suggests that the new timing of the signal reduces total delay for all
movements 27.05% (Morning peak) & 16.30% (Evening peak) than the existing
one. Particularly for movement 2 and movement 4 for morning peak &
movement 2 & movement 5 for evening peak, delay reduces most. In case of
morning peak, it is found from the analysis that for movement 2 and movement 4
delays reduce 40.59% and 39.77% respectively. On the other hand during evening
peak, movement 2 & movement 8 – delays reduces 22.33% & 21.95%
respectively from their existing conditions. The presented figures clearly
justify the improvement of the junction performance in new signal timing. Besides
the signal timing, some other problems are also identified which also affects
the operation of the intersection. These problems may not only play a vital role
to increase delay at intersection but also increase the chances of road crashes.
Pedestrian safety is also associated with them. Such types of problems arise
from improper road marking, illegal parking, unplanned buses stoppage, illegal
footpath usage etc. Photographs have been placed to show these problems.
Suggestions have been given to handle these problems by using scientific
judgment and applying engineering knowledge. |