Tips and Frequently Asked Questions

Please review these notes before contacting McTrans for technical support. If you do contact McTrans, please have your HCS 2010 registration number available. It can be found by choosing Help then “About HCS 2010” from within any module. Your version and registration numbers are just below the header information.

What’s new?

This version of HCS 2010 (release 6.50) implements the HCM 2010 Interchange Ramp Terminals (Chapter 22) procedures in Streets and adds the Quick Entry lane configuration tool to Roundabouts.

  • HCS+ Tips and FAQ, click here.
  • HCS2000 Tips and FAQ, click here.
  • HCS-3,Tips and FAQ click here.

 

Streets

This module (Streets) expands on Signals to provide for multiple intersections, including a new graphical interface option (Visual Mode) and two optimization choices: Quick Optimization (one-touch export to TRANSYT-7F), and Full Optimization (HCM-based internal genetic algorithm). A new automated time-space diagram shows progression quality at a glance.The HCM 2010 methodology now includes provisions for modeling the effects of access points between signals on travel speed and platoon integrity. A new flow profile graphic shows the arrival rate at a glance. The Streets module also includes the ability to model multimodal operations, including computing pedestrian, bicycle and transit levels of service for each segment and the facility.

Signals

Implementation of the Signalized Intersection procedures is now simply a one-intersection analysis within the Streets module. Because of this integration, the Signals module from the Main Menu has been disabled.

What’s coming?

The Two-Way Stop Control (TWSC) and All-Way Stop Control (AWSC) modules will be expanded to include the HCM 2010 changes to add three-lane approaches.

What is the license and support arrangement with HCS 2010?

HCS 2010 is distributed as an office license that includes technical support (automatic updates, downloadable updates, toll-free telephone assistance, data file review, etc.) for the first year. Thereafter, an annual support subscription must be maintained to continue these services, but no more upgrade fees are required.

Do I need to uninstall the previous version(s) of HCS?

HCS 2010 is a separate installation and does not automatically uninstall HCS+ (or any previous version). Although uninstalling the previous version(s) is recommended to avoid conflicts and confusion for most users, allowing multiple versions to co-exist on one computer can be managed if there is a need. Some issues to be aware of include: double-clicking on a data file within Windows Explorer will typically load it in the latest version; right clicking on a data file within Windows Explorer to use ‘Open With’ can show multiple versions without information to tell them apart; and information like agency data, default file paths, some default data, recent file list, window position, etc. is stored in the Windows registry, and changing this for one version will likely affect the others.

What are the computer requirements for this version?

HCS 2010 is a typical Windows installation and the system should meet the following minimum requirements including Windows XP/Vista/7 or newer, 512MB RAM, VGA+ Monitor and 750 MB hard drive space available. This will be a completely new installation, separate from any existing version. The installation program will present a license agreement, which must be agreed to for the installation to proceed.

Are there any issues with running HCS 2010 in 64-bit Windows 7?

No issues have been discovered in testing or reported by users.

Do I have to have CORSIM installed for Quick Animation to work?

Yes, CORSIM for HCS (distributed with HCS 2010) has to be installed to generate the animation through CORSIM. To perform simulation analyses beyond animating HCS 2010 data, comp data, complete CORSIM (TSIS) must be installed separately.

Streets: What are the ‘Auto-Calculate’ and ‘Force Calculations’ icons used for?

Auto-Calculate is the default behavior for all HCS modules, including Streets. When Auto-Calculate is enabled, output values in the report are updated dynamically with each change to the input data. Streets is the only HCS module that allows Auto-Calculate to be turned off by the user, because the Streets calculations are complex and sometimes time-consuming on the computer. When the dataset has a large number of intersections and/or time periods, or when a slow computer is being used, the program sometimes needs several seconds to re-calculate. Turning off the Auto-Calculate feature allows the user to perform data entry more quickly, because the program will never pause to perform calculations. Once the data entry process is complete, the user can select either Auto-Calculate or Force Calculations. Both of these options will refresh output data in the reports, but only Force Calculations will allow the dynamic calculations to remain disabled. The analyst can use Auto-Calculate and Force Calculations in whatever way is most efficient for the size of their dataset and/or speed of their computer.

Streets: Why do the reports look disabled or grayed out? Why does ‘Phasing View’ look disabled or grayed out?

When the Auto-Calculate feature is turned off, output data are no longer updated in response to input data changes. This leads to situations in which output data will no longer be consistent with input data. The ‘stale feature’ (disabling or graying out) is used to notify the analyst that the output data are no longer up-to-date. This output data may include any of the formatted reports and text reports, and may include signal timings displayed by Phasing View. As soon as the user clicks on Auto-Calculate or Force Calculations, all outputs will be refreshed and the stale appearance will go away.

Streets: How do I code phasing?

The signal phasing sequence is specified by clicking on the Quick Phases dual-ring (NEMA) phasing diagram (phases 1 through 8). Only left-turn phasing needs to be specified, because thru movements and right-turn movements are automatically added to the phasing sequence as a function of laneage. Left-turn movements in odd-numbered phases are used to reflect protected left-turns (i.e., ‘green arrow’), whereas left-turn movements in even-numbered phases are used to reflect permitted left-turns (i.e., ‘green ball’). When exclusive right-turn lanes exist, shielded right-turns may be added by clicking twice on the corresponding odd-numbered phase. After the signal phasing and timing are entered a sequential phasing diagram (labeled ‘Phasing View’) will display the overall timing plan in an equivalent ‘single-ring’ format equivalent to how phasing was coded in previous versions.

Streets: What do the green times in Phasing View represent?

After the signal phasing and timing are entered, the Phasing View diagram displays the overall timing plan in an equivalent “single-ring” format. The HCM2010 procedure to calculate the average duration of an actuated phase generates the green times in the Phasing View. This procedure is used for estimating the average phase duration for an intersection that is operating with actuated control. Where appropriate, the description is extended to include techniques for estimating the duration of non-coordinated and coordinated phases. For pre-timed signals (Recall Mode set to Max for each phase), phase durations will usually reflect user-specified maximum green times. Alternatively, phase durations may be taken directly from user-entered data, by turning on the checkbox called Field-Measured Phase Times.

Streets: What is the difference between Demand used instead of Volume in Signals?

Demand is the arrival rate and Volume is usually taken to mean stop bar counts. Stop bar counts do not represent demand for congested conditions. In Signals, this plays a significant role in the determination of residual queues that are used to compute diod is essen delay. Counting the remaining queue at the end of each period is essential for determining total demand for every movement and period. For oversaturated situations, this can make a very significant difference in the computation of overall delays and level of service.

Streets: Why is there only one Peak Hour Factor field?

The Peak Hour Factor (PHF) specifies the proportion of peak-hour volume occurring in the peak 15 minutes for the entire intersection as prescribed by the HCM2010 for planning purposes. Peak 15-minute volume is computed as the hourly volume divided by four times the PHF. For operational applications, a multiple-period analysis using 15-minute Demands directly should be used which precludes the need for the PHF entirely.

Streets: What is the advantage in running a Multiple-Period analysis in Signals?

The HCM2010 states that for operational analyses, demand flow rates for each analysis period be provided. This is usually multiple periods to span the time normally needed for analyzing the peak hour(s). A multiple-period analysis can model the unmet demand that may exist from one 15-minute period to the next in oversaturated conditions. This analysis will estimate the residual queues for each period and use them as the initial queues for the subsequent period for each lane group. This will allow for a more accurate computation of additional delays (d3) attributable to these queues for the overall analysis period. This type of analysis should include under-saturated conditions for at least the first and last periods. Running a multiple-period analysis for any situation (including under-saturated conditions) also overcomes the dilemma in using the appropriate 15-minute period versus a peak-hour factor (PHF) that could vary among movements and periods.

Streets: What other requirements are there when collecting data for a Signals analysis?

There are several types of information required for a Signal analysis that can be obtained while performing turning movement counts: Residual queues (see above) for each period for all approaches; parking maneuvers per hour within 250 ft. of the stop bar; heavy vehicle percentages by movement; buses stopping per hour within 250 ft. (near side or far side); unequal lane distribution for a multiple lane movement; and right turns on red, pedestrians, and bicycles per hour on each approach.

Streets: What is the I-Factor in Signals and how is it computed?

The Upstream Filtering Adjustment Factor (I) accounts for the filtering effects of upstream signals within a mile of the analysis signal on each approach. It is based on the weighted average of the v/c ratios of the contributing movements from the upstream signal (automated in Signals) and can make a significant difference in the d approachin delay, especially where the subject approach has v/c ratios approaching or exceeding 1.0.

Streets: How are Arrival Type values in Signals determined?

Arrival type is used to describe the quality of signal progression for the corresponding movement group. Values of arrival type range from 1 to 6, with 1 representing poor progression, 6 representing exceptional progression, and 3 representing random vehicle arrivals. Typically, arrival type 3 is used for all uncoordinated, including actuated, movements and arrival type 4 is used for most coordinated movements.

Streets: What is the Queue Storage Ratio in Streets and is it important?

The Queue Storage Ratio (QSR) is the Maximum Back of Queue (HCM Chapter 16 Appendix G) divided by the Available Queue Storage Length. If the QSR is equal to or greater than 1.0, blockage will occur. The HCM procedures do not account for this blockage in the computation of delay and these situations must be simulated (with CORSIM) to get reasonable results.

TWSC: Does the median type make a difference in a Two-Way Stop-Controlled analysis?

The computation of two-stage gap acceptance differs for the minor-street thru movements depending on the type of median. A “Raised Curb” median assumes the minor-street thru can utilize this storage to perform the movement in two steps. A “TWLTL” median will assume the minor-street thru movement will be accomplished in one stage.

Why won’t my formatted report print on one page?

Since these reports use the Internet Explorer for display and printing, adjustments may need to be made there for these reports to print on one page. To suppress the automatic header and/or footer, simply blank the appropriate field(s) in the “File > Page Setup” screen. Setting margins to 0.25″ on this screen is also advisable. You may also have to reduce the text size in View > Text Size.

Why does the last field with data sometimes not get used in the calculations or saved in the file?

Users must be sure to hit Tab, Enter or click into another field before viewing or printing results to ensure the last entry has been recognized. When a data file is saved, the last entry is automatically stored.

Known Issues:

Streets: The loading and refreshing of the Streets module is slower than the others, due to the very large number of fields and the magnitude of the computations.

Streets: Side-street approaches with only left and/or right movements must be coded with a thru movement having a zero volume to be computed properly.

Streets: For intersections of two one-way streets where either phase 2 or phase 6 does not exist, unopposed left-turn movements cannot be coded off the major street. To overcome this, the left-turn demand can be included with the thru demand and the base saturation flow rate adjusted using the Percent Unopposed Left Turns field in Detailed Data.

Streets: When an approach has more than four lanes, the Quick Lanes graphic may not print properly on some printers. You can close and reopen the data file, go to Print Preview, print to the Microsoft XPS Document Writer, then print the resulting .xps file to your printer.

Streets: Quick Optimization (via TRANSYT-7F) requires at least one exclusive movement group.

Roundabouts: Volume data for right-turn bypass lanes may not get saved properly in some data sets.  Please contact McTrans if you have this issue.

Ramps: For a diverge analysis, an upstream on-ramp is not correctly applying the equilibrium length check. Please contact McTrans if you have this situation.

Ramps: For a five-lane analysis, the capacity check does not consider the appropriate value. Please contact McTrans is you have this situation.

Warrants: The Grade Crossing Approach field may not get saved properly in some data sets. Please contact McTrans if you have this issue.