References1. HCS 2010 online manuals.2. Data Data provi.docx
- 1. References: 1. HCS 2010 online manuals. 2. Data: Data provided for Lab 6 3. Software: HCS 2010 Objectives: The objective of this exercise is to become familiar with operational-level signal timing software. The software you will use is the implementation of the Highway Capacity Manual 2010. General notes regarding this lab: · The intersection you will be using for analysis is Lake Mary Rd. and High Country Trail. Take a look at this intersection on Google Maps. Draw a rough sketch of the intersection, showing lane usage. Be sure to include a North Arrow, as well as movements (with numbers….use movement 2 for Northbound through). (2) · Operational data for this intersection is provided in the file ‘Lab6data.xlsx’ open this file. · The timing data given is for pretimed 2-phase operation. What is the cycle length given? (1) Background: The HCS2010 software does not exactly duplicate the HCM 2010 methods but it is reasonably close. One difference is in the optimization algorithms, which are specific to the software and are not specified in the HCM 2010. The software will not design your timing plan for you (It can, but we will not be using that option). It is used as a calculation tool to help you determine which combination of green interval lengths and cycle length provide the best LOS (or lowest delay) with safe operation. A proper phase plan is a critical aspect of signal timing design. Once the phase plan has been developed, most of the signal timing can be systematically treated in a deterministic fashion. There are several important considerations you need to keep in
- 2. mind when establishing a phase plan for your intersection: 1. Safety: Phasing can be used to minimize accident risks by separating the competing movement. A traffic signal always eliminates the basic through crossing conflicts present at the intersections. 2. Lost time per cycle: In addition, left-turn protection can also be used to eliminate the conflicts between left-turning movements and the opposing through movement. However, additional phasing can also lead to more lost time per cycle and therefore additional delay. 3. Sat flow rates for LTs: While increasing the number of phases also increases the total lost time in the cycle, a benefit is that this also increases the affected left-turn saturation flow rates. This in turn can lead to less delay. Lab Steps: 1. Open the HCS2010 software on a PC in Rm. 114 or 113. Open the traffic signals module. 2. When you start a new traffic signal file, a dialog box will appear asking you to verify settings of the intersection. The only setting you need to adjust is that of the forward direction, which is used for arterial analysis. Even though we will only be working with one intersection, you should still choose NB for this. All other settings can be left at their default. 3. You will be entering data in the following sections: a. Primary Input Data (All Sections), shown in Figure 1 b. Detailed Input Data (General and Intersection sections) Figure 1: Primary Input Data 4. Enter the data you were provided in the spreadsheet file.
- 3. a. Primary Input Data, General: i. The duration of the analysis period is 0.25hr. ii. Area Type: Other iii. PHF: From Data iv. Geometry: Click on buttons on intersection diagram b. Primary Input Data, Traffic: i. Much of this section is related to determination of the saturation flow rate for the different lane groups. With the exception of the Storage Length values (use 400’ for each movement), leave the default values for now. We will address this later. ii. Enter your volume data. iii. Use 60’ detectors. iv. The Speed Limit is 45mph on Lake Mary Rd., and 35mph on High Country Trail. v. Ignore ‘Upstream Filtering,’ ‘Initial Queue,’ and ‘RTOR.’ c. Primary Input Data, Phasing, Phasing View, and Timing: i. Using the help available for the software, setup the pretimed phasing plan provided. Items to note: 1. Check the boxes labeled ‘Field-Measured Phase Times’ and ‘Uncoordinated Intersection.’ This will force the software to perform the analysis with the values entered by you. 2. To force pretimed operation, set the recall mode of each
- 4. operating phase to ‘Max.’ d. Detailed Input Data, General (upper left): i. Fill in the details of your analysis. e. Detailed Input Data, Intersection: i. Enter the number of lanes for each approach. Be sure to check whether or not the lanes are shared. (This will populate for you if you already did this with the intersection diagram) ii. Leave other values at their default. 5. While you have been doing this, the software has been constantly performing an analysis on the data you have entered, an example of which is shown in Figure 2. Important items to note for analyzing the impact of input data changes are the control delay (and corresponding Levels of Service) for each movement, each approach, and the entire intersection. V/C is also critical information regarding the performance of a movement. (These outputs are similar to those seen when using Synchro, though they are calculated a little bit differently) 6. Based upon the data you have entered so far, what is the Intersection Level of Service? What value is used to determine the Level of Service? (1) 7. Save your file as Lab6_base. 8. Print a copy of the output (1-page). Label this printout ‘Base Timing,’ and append it to the back of this document (1) 9. Now, we will change some of the input data to see what impact it has on the Levels of Service. 10. Change the Lane Width for EB right to 9’. 11. What did this do to the Adjusted Saturation Flow Rate for the EB right movement? List the values for before and after the
- 5. change. Also, comment on why this is the case. (3) 12. Change the Lane Width back to 11’ for the EB right movement. 13. Provide a definition for Arrival Type. You may use your class notes. (2) 14. The Arrival Type for all movements is currently 3. Change the value for Arrival Type to 1 for the NB and SB through movements. Observe the control delay for each of those movements on the output sheet. List the values below: (1) 15. Change the Arrival Type to 6 for both the NB and SB through movements. Observe the control delay for each of those movements on the output sheet. List the values below: (1) 16. The changes in Arrival Type should have had a drastic impact on the control delay for these movements. Why is this the case? (2) 17. Set the Arrival Type back to 3, and save your file as Lab6_pretime_optimized. 18. Using the settings in the Phasing and Timing data entry areas, optimize the two phase timing plan provided. Use a maximum cycle length of 120s, and a minimum of 30s. List your phase timing information below (G, Y, and AR) for each phase, as well as your cycle length. Attach a copy of the output for the optimized pretimed plan, labeled ‘Pretimed Optimized.’ (4) 19. Describe the process you worked through to optimize the pretimed plan. What worked well? What didn’t work well? (4) 20. Save a final copy of your optimized pretimed plan. 21. Open the Lab6_base timing plan. Save it as Lab6_actuated. 22. Now, you will develop and optimize an actuated timing plan
- 6. for the intersection. For this, you will determine the number of phases, as well as the phase sequence. 23. First, you must come up with a phasing plan. Using the NEMA ring diagram templates below, come up with three possible phasing plans. Use NB for Phase 2. Be sure to show protected and permitted movement arrows in your ring diagrams, draw barriers in the proper location, and cross out phases that will not be used. List one benefit, and one drawback of each plan. (8) Alternative 1 Alternative 2 Alternative 3 24. Choose one of your alternatives to implement in the software. Which one did you choose, and why did you choose this plan? (2) 25. To implement an actuated timing plan in the software, change the Recall Mode for each phase to ‘Off.’ Change the phasing to match your preferred alternative, and optimize the green durations / cycle length per instructions provided in Step 18. Provide a screen capture of the input data (it will look very similar to Figure 1). Label this ‘Optimized Actuated Input Data’ and append it to the back of this document. (2) 26. Explain the process you went through to optimize your actuated timing plan. (2) 27. Print out a copy of the analysis output, label it ‘Optimized Actuated Output’ and append it to the back of this document. 28. Complete the delay summary table below (2). The units of
- 7. the delay are sec/veh. Control Delay Eastbound Northbound Southbound L T R L T R L T R Base Pretimed Plan Pretimed Optimized Plan
- 8. Actuated Optimized Plan 29. Select four operationally significant differences from the table you just completed, and explain why they occurred. (4) 30. Given the conditions at the intersection (you may need to visit the intersection to answer this question), which type of control (pretimed or actuated) do you feel is most appropriate for this intersection? Address the benefits and drawbacks of each type of control, how they apply to this intersection, as well as the differences in total delay you found for the two types of control. (4) Figure 2: Analysis output Saturation Flow Data
- 9. Page 1 Sheet1SouthboundNorthboundWestboundEastboundMovementL eftThruRightLeftThruRightLeftThruRightLeftThruRightPHFTim e Period (Monday AM Peak period)7:00 AM - 7:15 AM039109360000560241737:15 AM - 7:30 AM050139370000650282027:30 AM - 7:45 AM0551411430000730312277:45 AM - 8:00 AM0601514570000600262318:00 AM - 8:15 AM0561412470000690302288:15 AM - 8:30 AM0511312470000780332349190.988:30 AM - 8:45 AM0551412490000600262158:45 AM - 9:00 AM056141663000037016202Sum the total volume in the peak hour for each movement to get the demand volume for that movement.Peak Hour Highlighted in YellowTiming DataGYARSplitNB / SB254130EB254130Pedestrians: We will be ignoring the impact of pedestrians in this lab. Sheet2 Sheet3