Question

Problem 2 (Traffic Steam Characteristics): For the same lane as described in Problem 1, a snapshot was taken at 9:01AM. The spacing between the front bumper of a vehicle and the front bumper of the following vehicle was measured as shown in the following table. Answer the following questions:

Table 2: Spacing Data

Vehicle ID	Spacing (feet)
1	/
2	101.8
3	179.4
4	142.3
5	99.6
6	81.9
7	77.1
8	105.4

(1) Determine the average spacing.

(2) Determine the density of the segment by using the relationship between the density and the average spacing.

(3) Determine the density by using the conceptual meaning of it (i.e., the number of vehicles divided by the length of the segment[qw1] ).

(4) Compare the two density values you got from part (2) and (3). Are they the same? If not, which value you will choose as the density? Explain why.

(5) In which situations, the density values calculated from the two approaches (i.e., Part (2) and (3)) will converge?

[qw1]correction.

Answer 1

Given Vehicles and their spacing meas ored rom otbumper ob a vchick to the front bum per el the bllouoing vehicles in tabolar borm.(So,leath % he ron Vehicle is included To detrmine Variovs par. Calcolation - ) a vevage spacing ava tol 8+94 12:34 9961813 9 1+651 Sang5 feet 9- Ans )

a)= Density 6人segment (Us ing tae relationship betocen the dentity and average spaeing etween the densi t-e Density (k)- average spacin k- 5280-, 46-33 112.5 (vehicles mile Ans b) 3) Densitu oh seament (using Conceptval meavn Density (k) No oh vehiclk s lcngth o sgmert Uele twhile measuring spacing, lew t ob laat vehicle tvasn measure, so taki avrage length ab vehicle 19.9-ft . leng th ob segment 875+ 19..807 2f so, Density (k) 8092ft 6,2/s 0i R2 9p 5.080 2 45.988 k 46 (vehicles /mile 80 2 Ans (3)