Introduction to Transportation Engineering

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

2. Traffic Assignment

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

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

5. 2 Tree table from Node 1 1 7 3 3 5 3 4 3 4 6 3 9 2 3 5

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

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

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)

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

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

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

12. Exercise 2 250 C A E G 3 700 1 1000 2 6 6 3 9 4 2 800 950 5 8 2 H D F B 200

13. Tree Table Node A Tree Table Node B C A E G 3 1 2 7 7 3 9 4 3 3 8 1 H D F B

15. Traffic Assignment

16. Sketch of tree with allocated traffic: C A E G 1500 1750 800 0 0 950 0 800 200 950 0 200 H D F B

17. Stream Flow

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).

19. time mean speed (TMS) utms= 1/n ∑ vi utms=( 35+25+30+25+40+40+25+20)/8= 240/8=30 (miles/hour)

20. space mean speed (SMS) usms