=========================preview======================
(CIVL262)2009_s_CIVL262-Quiz1-solution_by_PPSpider.pdf
Back to CIVL262 Login to download
======================================================
CIVL 262 C Introduction to Transportation System Tutorial Quiz 1 13 Feb2009
Name : Student ID : Space and time mean speed
QUESTION 1

Two groups of cars are running on the highway. In the observation section, the traffic speed and spacing of each group maintain constant during a long time period. The speed of group A is 20 km/hr, the speed of group B is 50 km/hr. And the spacing of group A is 50m, the spacing of group B is 100m. Please calculate the time mean speed and space mean speed.

Solution:

Assume observation is L m
LL
20 + 50
50 100

Space Mean Speed vs == 30 km / hr
LL
+
50 100

s
Headway hi = i
v
i

50 m 100 m
hA == 9sec;hB == 7.2sec
20 km / hr 50 km / hr 3600
Flow qi = hi
3600 .1 3600 .1
qA == 400 hr ; qB == 500 hr
9 7.2
q v + q v
AA BB

Time Mean Speed vt = 36.67 km / hr
q + q
AB