1. CE 4640: Transportation Design Prof. Tapan Datta, Ph.D., P.E. Fall 2002

2. IMPLEMENTED OFF PEAK SIGNAL TIMING PLAN North-South Telegraph Road G = 31.2 sec Y= 4.7 sec R= 34.1 sec AR = 2.0 sec G = 25.8 sec Y = 4.3 sec R = 39.9 sec AR = 2.0 sec Inside G = 23.8 sec Y = 4.3 sec R = 41.9 sec AR = 4.0 sec Outside Cycle Length = 70 sec East-West Maple Road IMPLEMENTED PM PEAK SIGNAL TIMING PLAN Cycle Length = 120 sec North-South Telegraph Road G = 62.2 sec Y= 4.7 sec R= 53.1 sec AR = 2.0 sec G = 44.8 sec Y = 4.3 sec R = 70.9 sec AR = 2.0 sec Inside G = 42.8 sec Y = 4.3 sec R = 72.9 sec AR = 4.0 sec Outside East-West Maple Road Telegraph Road and Maple Road Intersection

3. N TELEGRAPH RD Figure 14. Vehicle Position vs. Proposed Signal Timing for the Intersection of Telegraph Road and Maple Road Position 1: Vehicle entering intersection 0.1 seconds before onset of red signal MAPLE ROAD 14´ 12´ 14´ 12´ 14´ 12´ 14´12´ 44´ 86’ 9’ 13’ 33’ 80’ 8’12’ LEGEND Vehicle Traveling at 35 MPH Position 1 Position 2 Position 3 Position 4 Note: North-south signal changes from red to green 5.2 seconds after the time of position 1. SB Telegraph (EB Maple Near) NB Telegraph (EB Maple Far) Vehicle entering intersection 0.1 seconds before onset of EB near red signal Position 1 (0.1 seconds before near signal turns red) Position 4 (5.2 seconds after time of position 1) Position 2 (3.1 seconds after time of position 1) Position 3 (5.1 seconds after time of position 1)

4. N Position 1: Vehicle entering intersection 0.1 seconds before onset of red signal TELEGRAPH RD Figure 13. Vehicle Position vs. Signal Timing Proposed for the Intersection of Telegraph Road and Maple Road MAPLE ROAD 14´ 12´ 14´ 12´ 14´ 12´ 14´12´ 44´ 86’ 9’ 13’ 33’ 80’ 8’12’ LEGEND Vehicle Traveling at 30 MPH Position 1 Position 2 Position 3 Note: North-south signal changes from red to green 5.2 seconds after the time of position 1. Position 1 (0.1 seconds before near signal turns red) Position 4 (5.2 seconds after time of position 1) Position 2 (3.1 seconds after time of position 1) Position 3 (5.1 seconds after time of position 1) SB Telegraph (EB Maple Near) NB Telegraph (EB Maple Far) Vehicle entering intersection 0.1 seconds before onset of EB near red signal Position 4

5. N TELEGRAPH RD Figure 12. Vehicle Position vs. Signal Timing for the Intersection of Telegraph Road and Maple Road Position 1: Vehicle entering intersection 0.1 seconds before onset of red signal MAPLE ROAD 14´ 12´ 14´ 12´ 14´ 12´ 14´12´ 44´ 86’ 9’ 13’ 33’ 80’ 8’12’ LEGEND Vehicle Traveling at 35 MPH Position 1 Position 2 Position 3 Position 4 Note: North-south signal changes from red to green 4.1 seconds after the time of position 1. Position 1 (0.1 seconds before near signal turns red) Position 4 (4.1 seconds after time of position 1) Position 2 (2 seconds after time of position 1) Position 3 (4 seconds after time of position 1) SB Telegraph (EB Maple Near) NB Telegraph (EB Maple Far) Vehicle entering intersection 0.1 seconds before onset of EB near red signal

6. N Position 1: Vehicle entering intersection 0.1 seconds before onset of red signal

7. Highways Hierarchy of Movements Primary Movement Terminal Access Collection Transition Distribution

8. Highways Functional Classification Mobility Land Access Arterials Collectors Locals

9. Arterials Primarily for through traffic movement Land access is a minor function All traffic controls and facility design intends to provide efficient through movement

10. Collectors Serves both through and land-access functions Not efficient for long through trips Good for through movements along with distribution and collection

11. Locals Primarily serves land-access functions Facilitates the movement of vehicles onto and off the street system from the land parcels Through movement is not desired and recommended

12. Highway Geometric Features Horizontal alignment Vertical alignment Cross-section design Channelization

13. Geometric Design Design criteria Design speed Safe stopping sight distance Passing sight distance (for 2-lane rural highways)

14. Horizontal Alignment W= Weight of vehicle (lb)  = Angle of pavement slope v = Velocity (ft/sec) e = Superelevation = tan  (ft/ft) F = Side friction = fW cos  f = Coefficient of friction g = 32.2 ft/sec 2 R = Radius of curve (ft)

15. Horizontal Alignment R = where R = min. radius of curvature (ft) v = design speed (mph) e = rate of superelevation (ft/ft) f = coefficient of side friction v2v2 15(e+ f)

16. Horizontal Alignment Example: for a highway facility with a design speed of 70 mph, e = 0.08 and f = 0.10, the minimum radius of curvature is calculated as: R = = 1814.8 ft Maximum ‘e’ allowed = 0.12 ft/ft as per AASHTO Green Book. (70) 2 15(0.08 + 0.10)

17. Horizontal Alignment Degree of Curvature Angle extended at the center of a circular curve D = where D = Degree of curvature R = Radius of curvature (ft) 5729.6 R

18. Vertical Alignment

19. Crest Vertical Curves Minimum length of crest vertical curves with S < L: L = ( for stopping sight distance) L = ( for passing sight distance) Minimum length of crest vertical curves with S > L: L = 2S - ( for stopping sight distance) L = 2S - ( for passing sight distance) AS 2 1329 AS 2 3093 1329 A 3093 A L = Min. length of vertical curve (ft) A = Algebraic difference in straight grades being joined (%) S = Required sight distance (ft)

20. Sag Vertical Curves Minimum length of sag vertical curves with S < L: L = Minimum length of sag vertical curves with S > L: L = 2S - AS 2 400+3.5S A L = Min. length of vertical curve (ft) A = Algebraic difference in straight grades being joined (%) S = Required sight distance (ft)

21. Cross-section Design Traveled way Number, width, cross-slope of travel lanes Roadside Shoulder Embankment Traffic barrier Curb Sidewalks Others Median

22. Channelization Separates traffic movements By paint markings By physical barriers

23. Intersection Design Should do the following: Reduce number of conflict points Control relative speeds of intersecting roads Coordinate design with traffic control Consider alternative geometry Separate conflict points Spatially Temporally Reduce area of conflict

24. Traffic Studies Data Types Physical inventory Population characteristics Operational data Special-purpose data

25. Physical Inventory Data Details of existing street and highway network including: streets and highway links traffic control devices Parking provisions roadway defects

26. Condition Diagram Shows all physical inventory data with necessary dimensions Collect data from the site Draw the condition diagram using any drawing tool, like MS PowerPoint, AutoCAD

27. 10’ 11’ 5’ 39’ ONLY 58’ Mobile Gasoline Station ONLY 6’ 11’7’ 12’ 14’ 12’ 10’ 13’ 14’ 11’ 15’ 14’ 10’ 12’14’ 13’ 11’ Precision Tune 12’ 14’ 12’ 11’ 12’ ONLY 28’33’43’ 26’52’ Thrifty Flowers and Plants Street Name Signs ONLY Street Name Signs 20’ 11’5’ 19’ 70’ Left-Turn Signals Right Turn Arrows 20’ 12’ Sunoco Gasoline Station 6’ 18’ Right Lane Must Turn Right Sign 44’ 37’ FIVE MILE ROAD MIDDLEBELT ROAD Condition Diagram of Middlebelt Road and Five Mile Road Intersection

28. Managing the Inventory System Advanced tools, like Geographic Information Systems (GIS) combines Geographic data with latitude and longitude Roadway network data Transit network data Roadway inventory data Crash data Socioeconomic data Others

29. Population Characteristics Data Data on the road users Number of road users Vehicle type Roadways used Amount of driving (say, annual) Reaction time Crash experience Others

30. Population Characteristics Data Sources of Data Secretary of State State Police Interviewing drivers with a specific set of questions Others

31. Operational Data Volume data Using traffic counters Manual counting Speed data Using speed gun at a spot Density data Calculated using volume and speed data

32. Operational Data Travel Time and Delay data By traveling through a specific roadway Headway and Spacing data Using electro-mechanical device

33. Special Purpose Data Crash data From the department of State Police Parking studies Manual survey and interview Pedestrian studies Manual survey and interview Older driver studies Driver and crash information and interview

34. Purpose of Traffic Studies Data collection Manually Using any device From available hard copy or electronic data Data reduction Compiling raw data into a shorter form Data analysis Analytical process to interpret the data

35. Traffic Stream Parameters Macroscopic Traffic stream as a whole Microscopic Individual vehicle characteristics

36. Macroscopic Parameters Flow (Q) number of vehicles traversing a point of roadway per unit time (vehicles/hour) Density (K) number of vehicles occupying a given length of lane or roadway averaged over time (vehicles/mile) Speed (V) distance traversed by a vehicle per unit time (miles/hour)

37. Q-K-V Relationship Flow, Q (veh/hr) = Density, K (veh/mile) x Speed, V (miles/hr) For example, say, Flow, Q = 1200 veh/hour Speed, V = 30 miles/hour Density, K = Q/V = 1200/30 = 40 veh/mile

38. Q-K-V Relationship Maximum Flow Flow (veh/hr) Density (veh/mile) Speed (miles/hr) Flow (veh/hr) Jam Density Critical Density Critical Speed