Abstract: The main objective of this research is to develop traffic speed curve that effectively can
describe road humps on performance measures and characteristics of traffic stream on multi-lane road.
The traffic speed has been measured in 50 m distance before and after the hump for three hump types. In
addition, the traffic stream characteristics have been measured 50, 25, 10 m before the hump. The hump
type I is a hump with dimensions of 3 m width and 0.15 m height lies in the 26th of July Corridor road
which is eight lanes of three meter width for each lane. The hump type II is a hump with dimensions of 4
m width and 0.15 m height lies, also in the 26th of July Corridor road. The type III is a hump with
dimensions of 9 m width and 0.2 m height which lies in the Nile Corniche road. This road is eight lanes of
three meter width for each lane plus median of one and half meter. Based on the research results, the
hump type I, the decelerating rate of vehicles speed before the hump is steeper than its accelerating rate
after hump for holiday as well as workday. However, for hump type II, the decelerating rate of vehicles
speed before the hump is almost the same to its accelerating rate after hump for holiday as well as
workday. Furthermore, for the hump type III, the decelerating rate of vehicles speed before the hump is
steeper than its accelerating rate after hump for holiday but these rates before and after that hump are
almost the same during workday. Regarding the traffic stream characteristics, it has been found that, for
all the hump types, the speed decreases while, the density increase by approaching the hump. In
addition, the speed 10 m before the hump ranged between 30.90 to 34.76 km/h. for the three humps. The
maximum speed 10 m before the hump was at hump type III, which indicates the decrease of hump effect
on speed as its width increase. On the other hand, the jam density 10 m before the hump ranged
between 94 to 119 veh. /km /lane. The maximum density was at hump type II. From the results of this
study, it has been concluded that, using wide humps (such as type III) increase the capacity of the road
section even just before the hump. |
