1. Introduction to Transportation Engineering Instructor Dr. Norman Garrick Hamed Ahangari 13th March 2014 1

2. Traffic Assignment 2

3. Type 1 Given: – Network – Cost (Impedance) Request – Short Path Tree – Short Path Sketch 3

4. Example 1 Find the shortest paths from node 1 to all other nodes 1 6 4 2 3 5 5 7 3 3 3 9 3 4 3 2 4

5. Node ( j )Total Impedance to Node j Node Preceding j 10- 264 374 431 586 651 1 6 4 2 3 5 5 7 3 3 3 9 3 4 3 2 Tree table from Node 1 5

6. Sketch of tree 1 6 4 2 3 5 5 7 3 3 3 9 3 4 3 2 6

7. Type 2 Given: – Short Path Tree Table – Cost (Impedance) Request – Short Path Sketch 7

8. Example 2 Use the following minimum tree table from node A to sketch the minimum tree including showing the travel time. (Employ short path method) Node (j)Total Impedance to Node jNode Preceding j A0- B 11C C 2A D 8C E 14B F 10C G 7 A H G I 15F J 25I K 18I L 15G 8

9. A 2 7 C G B D F 9 6 8 H L 2 8 I 5 J K 3 10 9

10. Exercise 1 Find the shortest path from node A to all other nodes A B C D E F G H 3 5 2 2 13 6 2 4 2 3 6 6 5 10

11. Type 3 Given: – Short Path Tree Table – Cost (Impedance) – Trip Interchange Request – Traffic Assignment 11

12. Exercise 2 A B C EG DF H 6 6 2 8 39 2 5 2 3 1 4 OriginDestinationTrip Exchange AF200 AH800 BE250 BG700 1000 950 700 800 250 200 12

13. A B C EG DF H 7 7 2 8 39 3 3 1 3 1 4 Node (j) Total Impedance to Node j Node Preceding j A0- B 6D C 1A D 3A E 4C F 4D G 6 E H 10G Node (j) Total Impedance to Node j Node Preceding j A6D B 0- C 6D D 3B E 9C F 4D G 11 E H 12F Tree Table Node A Tree Table Node B 13

14. TravelVolumeShortest PathLinks A-F200A D FAD-DF A-H800A C E G HAC-CE-EG-GH B-E250B D C EBD-DC-CE B-G700B D C E GBD-DC-CE-EG 14

15. LinkTrip A-FTrip A-HTrip B-ETrip B-GTotal Volume AD200 DF200 AC800 CE8002507001750 EG8007001500 GH800 BD250700950 DC250700950 Traffic Assignment 15

16. Sketch of tree with allocated traffic: A B C EG DF H 0 0 1500 0 9500 200 950 200 1750 800 16

17. Stream Flow 17

18. Example 1 In a study, the spot speeds of seven vehicles were observed to be 35, 25, 30, 25, 40, 40, 25 and 20 miles/hour, respectively. Calculate the time mean speed (TMS) and space mean speed (SMS). 18

19. time mean speed (TMS) u tms = 1/n ∑ v i u tms=( 35+25+30+25+40+40+25+20)/8= 240/8=30 (miles/hour) 19

20. space mean speed (SMS) 20