Traffic Signal Timing Coordination. Innovation for better mobility

Transcription

1 Traffic Signal Timing Coordination

2 Pre-Timed Signals All phases have a MAX recall placed on them. How do they work All phases do not have detection so they are not allowed to GAP out All cycles are a consistent length Page 2 2

3 Semi-Actuated Signals Main-street phases have a MAX recall placed on them. How do they work The main street does not have actuation so it is not allowed to GAP out All other phases are actuated Page 3 3

4 Fully Actuated Signals Closely spaced actuated signals without coordination are actually designed to stop cars. How do they work Terminates when a gap is present on the main street First car leaving a Signal has a gap in front of it Therefore Page 4 4

5 Coordination Multiple (2 or more) signals working together along an arterial Requirement A common cycle length Repeatable Pattern Good Coordination minimizes stops on the main street Bad coordination Can increase stops along the main street Page 5 5

6 Coordination Goals Maximize Progression Keep speeds up by reducing stops Limit Calls from Public Minimize Cross-Street Delay Page 6 6

7 Signal System Efficiency Measures Intersection Delay Amount of Delay for vehicles on ALL approaches Your logo here Page 7 7

8 Signal System Efficiency Measures Arterial Bandwidth Band of progression green time for vehicles traveling on Main Arterial sec 27 sec Page 8 8

9 Signal System Efficiency Measures Driver Perception Good if no stops on arterial Bad if waiting on cross street while no one on main street Page 9 9

10 Factors Affecting Progression Page 10 10

11 Factors Affecting Progression: Cycle Length Minimum Acceptable System Cycle Length Signal 3 Delay Signal 2 Signal 1 Cycle Length Page 11 11

12 Realistic Range of Cycle Length 1800 In this range, Limited increase in capacity Phases 3 Phases 4 Phases Page 12 12

13 Factors Affecting Progression: Intersection Spacing Every System has a Natural Cycle-length based on intersection spacing which will provide the best progression solution. Page 13 13

14 Factors Affecting Progression: Phasing Permissive Only Protected Only Protected + Permissive 3 lanes Can create yellow-trap with lead-lag phasing example: Lead- Lag Fewer number of phases = more time for progression band on main street 40 mph Your logo here Page 14 14

15 Effects of Lead / Lag Phasing Can significantly increase bandwidth Page 15 15

16 Optimization Models Synchro Based on least delay in system Passer 2 Based on green-band maximization Passer 3 Diamond Interchange Optimization Page 16 16

17 Data Requirements Turning Movement Counts Actual Speed along the arterial Intersection Geometry Number of Lanes (Capacity) Types of Signals faces (Phasing allowed) Street widths (for pedestrian timing) Intersection Spacing Page 17 17

18 Progression Optimization Process Page 18 18

19 PASSER2 Progression Efficiency Page 19 19

20 PASSER2 Time-Space Diagram Page 20 20

21 Synchro Data Input Page 21 21

22 Synchro Time-Space Diagram Page 22 22

23 Measures of Effectiveness Number of Stops Emissions Delay Travel Time Fuel Consumption Page 23 23

24 Measures of Effectiveness Process (PASSER3, PASSER2, and Synchro) Optimization Trimmier NB Trimmier SB Synchro Optimization Trimmier NB Trimmier SB Travel Time (min) 1:31 1:23 1:54 1:36 Total Delay (hr) Stops (#) Fuel Consumed (gal) CO Emissions (kg) VOC Emissions Page 24 24

25 Synchro - Simulation Page 25 25

26 Field Programming and Fine-Tuning To be outstanding in the field, you have to be out standing in the field! Observe real world field conditions Adjust timing on actual conditions Not everything can be any simulated Page 26 26

27 Detection and Coordination Page 27 27

28 Detection and Coordination Detection on the Non-coordinated phases Allows unused time to be given to a different phase which reduces delay Typically given to the coordinated Phase Can be shared with other non-coordinated phases Detection on the coordinated phases Can extend the coordinated phases past the force-off to allow the end of a platoon to progress through the intersection. Page 28 28

29 Controller Features How does a controller achieve coordination? Coordination has two critical Aspects 1 When/How do you get into a phase (Permissive Period) 2 When/How do you get out of a phase (Force-Off Point) Page 29 29

30 Permissive Period Opening of the permissive (When/How do you get into a phase) Open all permissives at once This can reduce cross-street delay. This gives unused time to the beginning of the coordinated phase. Open one permissive at a time in order as defined by the ring structure. This can favor the end of the coordinated phase. Your logo here Page 30 30

31 Cross-Street Benefits from Unused Coord Time Random arrivals (platoon through intersection) - allows coord phase to leave at beginning of PYP Unused PYP time given to cross street Page 31 31

32 Force Off Points When a phase uses all the time allocated by the coordination plan, a Force-Off is applied. The Force-Off as a third way to terminate a phase and exists only in coordination. The three ways are: Gap Termination Max Termination Force Off Your logo here Page 32 32

33 Force Off Points Two types of Force-Offs exist FLOATING FORCE-OFF Determined by when the phase actually comes on and how much time is programmed. This point can move from cycle to cycle (it floats). Will allow maximum early return to the coordinated phase. FIXED FORCE-OFF Predetermined as soon as a coordination plan is entered. It does not ever change (it s fixed). Will allow none coordinated phases to share time. Your logo here Page 33 33

34 Floating vs. Fixed Force-Off Reference Point: beginning of coord green Programmed Splits Page 34 34

35 Effect of Floating Force-Off Floating Force-Off and 7 Gap Terminate Early Return Programmed Splits Page 35 35

36 Effect of Fixed Force-Off Programmed Splits Fixed Force-Off Time not used by Increases time for the next phase Page 36 36

37 Floating vs Fixed Force-Off Which is better? Floating Force-Off Programmed Splits Fixed Force-Off Page 37 37

38 Reference Point Reference Point: end of coord green Programmed Splits Page 38 38

39 Offset Correction Dwell Electro-Mechanical way of getting into coordination. In step in 1 cycle Dwell Max - Dwells only for the programmed time. Shortway Automatically selects the shortest route (long or short) to get in step over the following 3 cycles. Your logo here Page 39 39

40 Shortway Correction Desired offset > 50% out of step < 50% out of step 50% out of step decision line Start of coordinated phases (actual offset) during recognition cycle (ex. 40% out of step) Your logo here Page 40 40

41 Shortway Correction Offset < 50% out of step If actual offset is less than 50% out of step the controller will decide to shorten each interval proportionally to achieve new offset in 3 cycles Desired offset Correction in 3rd cycle Correction in 2 nd cycle Correction in 1 st cycle Start of coordinated phases (actual offset) in old plan (ex. 40% out of step) Your logo here Page 41 41

42 Shortway Correction Offset > 50% out of step If actual offset is more than 50% out of step the controller will decide to lengthen each interval proportionally to achieve new offset in 3 cycles Correction in 3rd cycle Desired offset Correction in 2 nd cycle Correction in 1 st cycle Start of coordinated phases (actual offset) in old plan (ex. 60% out of step) Your logo here Page 42 42

43 Data Entry Requirements Cycle Length- The time required to services all the phases programmed times Split times The sum of the green + yellow + red times Offset the amount of time from the reference clock to the scheduled on time of the coordinated phase Coordinated Phases The reference phases on the arterial street (typically one in each ring) that is given a guaranteed green interval to provide progression Time of day plan The schedule of when each timing plan will run (day, timing plan, and special functions) Your logo here Page 43 43

44 Coordination Data Timing Rules Each Phase Split MUST Accommodate: OR Min Time + Yellow Time + Red Clearance Time Ped timing (which ever is longer) The sum of splits in each ring on each side of the barrier must be equal The sum of all splits in a ring CANNOT exceed the cycle length The offset CANNOT be longer than the cycle Length Your logo here Page 44 44

45 Coordination Troubleshooting How can you tell if a coordination plan is running? Check error logs Check to see if the coordination timer is running Your logo here Page 45 45

46 Coordination Example 1 Phase Min PASS Max Walk Clear Yel Red Cycle Length 90 coord phases 2+6 Offset 10 Phase Split Mode Your logo here Page 46 46

47 Coordination Example 1 Phase Min PASS Max Walk Clear Yel Red Cycle Length 90 coord phases 2+6 Offset 10 Phase Split Your logo here Page 47 47

48 Coordination Example 2 Phase Min Max Walk Clear Yel Red Cycle Length 70 coord phases 2+6 Offset 10 Phase Split Your logo here Page 48 48

49 Coordination Example 2 Phase Min Max Walk Clear Yel Red Cycle Length 70 coord phases 2+6 Offset 10 Phase Split Your logo here Page 49 49

50 Coordination Example 3 Phase Min Max Walk Clear Yel Red Cycle Length 70 coord phases 2+6 Offset 10 Phase Split Your logo here Page 50 50

51 Coordination Example 3 Phase Min Max Walk Clear Yel Red Cycle Length 85 coord phases 2+6 Offset 10 Phase Split Your logo here Page 51 51

52 Coordination Example 4 Phase Min Max Walk Clear Yel Red Cycle Length 90 coord phases 2+6 Offset 100 Phase Split Your logo here Page 52 52

53 Coordination Example 4 Phase Min Max Walk Clear Yel Red Cycle Length 90 coord phases 2+6 Offset 100 Phase Split Your logo here Page 53 53

54 Questions and Comments Page 54 54