0
7.2kviews
The consolidated data collected from speed and delay studies by floating car method on a stretch of urban road of length 3.5 km, running North-South are given below.

Determine the average value of (i) volume (ii) journey speed (iii) running speed of the traffic stream along each direction

Trip no Direction of trip Journey time, min-sec Total stopped delay, min-sec No of vehicles overtaking No of vehicles overtaken No of vehicles from opposite direction
1 N-S 6-32 1-40 4 7 268
2 S-N 7-14 1-50 5 3 186
3 N-S 6-50 1-30 5 3 280
4 S-N 7-40 2-00 2 1 200
5 N-S 6-10 1-10 3 5 250
6 S-N 8-00 2-22 2 2 170
7 N-S 6-28 1-40 2 5 290
8 S-N 7-30 1-40 3 2 160
1 Answer
1
409views

The mean value of journey time, stopped delay, no of vehicles overtaking,overtaken and in opposite direction for North-South and South-North directions obtained are given below.

Direction Journey time, min-sec Total stopped delay, min-sec No of vehicles overtaking No of vehicles overtaken No of vehicles from opposite direction
N-S 6-32 1-40 4 7 268
6-50 1-30 5 3 280
6-10 1-10 3 5 250
6-28 1-40 2 5 290
Total: 26-00 6-00 14 20 1088
Mean: 6-30 1-30 3.5 5.0 272
S-N 7-14 1-50 5 3 186
7-40 2-00 2 1 200
8-00 2-22 2 2 170
7-30 1-40 3 2 160
Total: 30-24 7-12 12 8 716
Mean: 7-36 1-40 3.0 2.0 179

(a) North-South direction

$n_y = \textit{average no. of vehicles overtaking minus overtaken} = 3.5 - 5.0 = -1.5$

$n_a$ = average no. of vehicles during trips in opposite direction ( fro S-N trips) $= 179$

$t_w = \textit{average journey time with the stream} , q = 6\hspace{0.05cm}min\hspace{0.05cm}30\hspace{0.05cm}sec = 6.5\hspace{0.05cm}min$

$t_a = \textit{average journey time during trips against the stream} = 7\hspace{0.05cm}min\hspace{0.05cm}36\hspace{0.05cm}sec = 7.6\hspace{0.05cm}min$

$\textit{Average volume}\hspace{0.05cm}(q) = \frac{n_a + n_y}{t_a + t_w} = \frac{179 - 1.5}{7.6 + 6.5} = 12.59\hspace{0.05cm}veh/min$

$\textit{Average journey speed} = \frac{3.5}{6.62}\hspace{0.05cm}km/min = \frac{3.5\hspace{0.05cm}\times\hspace{0.05cm}60}{6.62} = 31.7\hspace{0.05cm}kmph$

$\textit{Average stopped delay} = 1.5\hspace{0.05cm}min$

$\textit{Average running time} = \textit{Average journey time - Average stopped delay}$

$\hspace{3cm} = 6.62 - 1.50 = 5.12\hspace{0.05cm}min$ $\textit{Average running speed} = \frac{3.5\hspace{0.05cm}\times\hspace{0.05cm}60}{5.12} = 41.0\hspace{0.05cm}kmph$

(b) South-North direction

$n_y = 3.0 - 2.0 = 1.0\\ t_w = 7.6\hspace{0.05cm}min\\ t_a = 6.5\hspace{0.05cm}min\\ n_a = (\textit{for N-S strips}) =272\\ q = \frac{272 + 1.0}{6.5 + 7.6} = 19.36\hspace{0.05cm}veh/min\\ \overline{t} = 7.6 - \frac{1.0}{19.36} = 7.55\hspace{0.05cm}mm\\ \textit{Journey speed} = \frac{3.5\hspace{0.05cm}\times\hspace{0.05cm}60}{7.55} = 27.8\hspace{0.05cm}kmph\\ \textit{Average stopped delay} = 1.8\hspace{0.05cm}min\\ \textit{Average running time} = 7.55 - 1.80 = 5.75\hspace{0.05cm}min\\ \textit{Average running speed} = \frac{3.5\hspace{0.05cm}\times\hspace{0.05cm}60}{5.75} = 36.5\hspace{0.05cm}kmph$

Please log in to add an answer.