McTrans Newsletter
December, 1995

Signal Timing Using TRANSYT-7F


by Larry Hagen
Faller, Davis & Associates
(Formerly Acting McTrans Manager)

Introduction

The purpose of this project was to optimize the signal timings for the Tallahassee Central Business District (CBD) using TRANSYT-7F. This effort included a total of 56 signalized intersections and examined 5 different time periodsÄthe AM peak, the AM off-peak, the noon peak, the PM peak, and the evening off-peak. The objectives of this project were reduced stops and delays for motorists in the CBD, reduced fuel consumption, reduced operating costs, reduced vehicle emissions, and smoother traffic flow.

Data Collection

At the project outset, the City's files were researched to determine what traffic count data was available, how current it was, and what additional data would be needed. For the most part, the turning movement counts and geometric data for the project were current and available from the files. A few intersections did have to be counted since their counts were either non-existent or over two years old.

However, in was decided that rather than just accept the default values for saturation flow rate for use in the TRANSYT-7F analysis, the saturation flow rates would be developed using the Highway Capacity Manual procedures. This involved the development of a spreadsheet (Microsoft Excel) that was used for each movement at each intersection to compute saturation flow rates. This required a significant amount of additional field data collection to determine lane widths, approach grades, presence and use of on-street parking, etc. The spreadsheet then computed a saturation flow rate for each approach lane for each of the 56 intersections.

Preparation of TRANSYT-7F data sets

Once the traffic data was accumulated and all of the saturation flow rates were computed, the data was then input into EZTRANSYT PLUS. The purpose of the EZTRANSYT PLUS program is to make the preparation of TRANSYT data sets as easy as possible. Once all of the data had been input into EZTRANSYT PLUS, the base TRANSYT-7F data file for the AM peak was generated. Unfortunately, EZTRANSYT PLUS does not handle some of the unusual geometric or traffic situations that are present in the Tallahassee CBD. Therefore, from this point on, it was necessary to use the TRANSYT-7F data set that was generated by EZTRANSYT PLUS and modify it using TRANSYT-7F's native coding scheme. While this did decrease the "user-friendliness" of the data, it allowed much more detailed and thorough analysis by tapping the full power of the TRANSYT-7F program.

For developing the TRANSYT-7F data sets for the other time periods, the AM Peak data set was imported into a spreadsheet (Lotus 1-2-3 for Windows). Since TRANSYT's input data file is an ASCII file containing integers in 5 character blocks, it was easy to import the data into Lotus to manipulate. The spreadsheet was then set up properly to assign the link-to-link relationships for the TRANSYT-7F analysis (i.e., the NB thru at intersection 2 is fed by the three movements shown in the figure from intersection 1). Thus, to analyze another time period, the user puts in the turning movement count information for the new time period and the spreadsheet modifies the link-to-link flow accordingly. This spreadsheet format will be valuable tool for the City in the development of future timing plans and could conceivably be connected into the future signal system such that as traffic data is coming in from the detectors, the database for TRANSYT-7F would be continuously updated. The signal timing from the system database could also by dynamically linked to the spreadsheet. Therefore, developing new or updated signal timing plans would be a very simple matter.

Results of the Project

The results of the TRANSYT-7F runs indicate substantial reduction in delays, stops, fuel consumption (and hence emissions), and operating costs. The results show a conservative estimate in fuel and time savings of $7.68 million per year to the motoring public of Tallahassee with only one cycle, split and offset changes (no phasing changes or geometric changes were required). It is important to understand, however, that these dollars are not tangible dollars than can be put in a bank account or used by the City on other projects, but instead this represents an accumulation of each motorist saving a few cents per day over the course of the year. Again, while this money can not be captured by the City for future transportation projects, it does represent a very significant return on the signal retiming investment.

Traffic Demand Management Model Application

by Jack Henneman, COMSIS

The Clean Air Act Amendments of 1990 (CAAA) and the 1991 Intermodal Surface Transportation Act (ISTEA) require many planning organizations to evaluate and implement Transportation Control Measures (TCMs) to reduce air pollutants created by mobile sources.

COMSIS has been in the forefront in analyzing TCMs, including the development of the Travel Demand Management (TDM) Model. The TDM Model provides for quick, direct summary analysis of the probable impacts of a variety of TCMs and allows the user to evaluate the singular or combined effects of TCMs. The model also presents the user with a broad menu of strategies to formulate TCMs. These strategies include both employer-based and region- mode applications ranging from pricing measures to employer-based support functions. The TDM model directly interacts with many of the most popular travel demand modeling software packages and produces revised trip tables that can be run through highway and transit assignment procedures and emission models.

Over the last twelve months COMSIS has employed the TDM Model in a variety of contexts, including: a TIP conformity study for Virginia Department of Transportation, a TCM cost- effectiveness study of the Delaware Valley Regional Planning Commission, statewide TCM analysis for the state of Connecticut, and an evaluation of the potential impact of ECO programs for the Chicago Area Transportation Study.

For the Greater Hartford Rideshare Corporation, in conjunction with Connecticut Departments of Transportation and Environmental Protection, Connecticut Fund for the Environment, and United Illuminating (Connecticut's largest utility corporation), COMSIS conducted a statewide analysis of a comprehensive list of transportation control measures (TCMs). The primary objective of this study was to provide a basis from which to assess the ozone related air quality impacts of specific TCMs and their impact on the state's air quality conformity status. The secondary objective was to address the potential travel and societal costs and benefits of these measures.

COMSIS used its expertise in traditional travel demand modeling, emissions modeling, and the COMSIS TCM Model to quantify the travel, emissions, and socioeconmic the impact of the TCMs. In completing these objectives, COMSIS played a key role in formulating and analyzing a list of 15 viable individual TCMs and six logical TCM packages for three planning horizon years. COMSIS worked directly with the Connecticut Department of Transportation, integrating the resulting trip tables from the TDM Model with the statewide transportation travel demand mode, and the MOBILE 5.0 emissions model to quantify the transportation and air quality impacts. Special attention was given to designing TCM packages that addressed Connecticut's particular air quality and transportation needs in a holistic manner.

NEW PRODUCTS

FIPP

Formed in Place Pipe (FIPP) software is a Windows 3.1 application program which provides design solutions for relining existing pipe, whether partially or fully deteriorated, with HDPE, PVC or RIT liners (Trenchless Technology).

The help screens contain abundant design information from many sources, such as ASTM, AWWA and AASHTO. In addition, the Users Manual gives a complete description of the program contents and provides detailed instruction on its use, accompanied by numerous hand calculated examples. For design of fully deteriorated pipe conditions, appropriate liveload is calculated and integrated into the design solution for Highway, Railroad and/or Aircraft applications.

FIPP will operate on an IBM compatible 386, or higher with 4 MByte RAM, and 2 MByte free HD space.

Formed in Place Pipe Version 3.1 (#FIPP) by E. Gene Byrd, Civil Engineers Inc. is available for $225 at LOS 6. An installation and users guide is included.

FLEXSYT-II

FLEXSYT-II is an event-based, microscopic simulation tool for traffic management studies. It is the successor of FLEXSYT-I, developed in the seventies and eighties by Frans Middelham. On a stochastic base vehicles move through the network, interacting with each other and the network (e.g., stop-lines and detectors). It has a no build-in control philosophy and is therefore suitable to study a range of problems. FLEXSYT-II uses a special traffic control language, called FLEXCOL-76. FLEXCOL-76 is based on the rules of boolean algebra and the clear differentiation between the 'change of state of an element' (event) and the 'state of an element' (condition). The control part also has a special structure. This structure contains a general part (the control philosophy) and a problem dedicated part, both to be specified by the user.

The network has to be specified in detail and can contain features such as stops for public transport, secondary conflicts, priority intersections and routes. In the simulation eight vehicle types can be present. These types are person cars, small trucks, large trucks, busses, trams, bicycles, pedestrians and carpool vehicles. All these vehicle types have their own characteristics and traffic behavior. Output can consist of an event by event trace of the controller and tables containing an output on delays, queue lengths, network indicators and environmental aspects (fuel consumption and emission of toxic gasses).

With FLEXSYT-II it is possible to do research on the structure of the network, such as the lay-out of intersections, length and number of lanes, effects of bus lanes, etc. But, due to its own traffic control programming language, it can also be used to study all kinds of traffic control strategies, such as the fixed-time control strategy, vehicle-actuated control strategies, traffic-depended control strategies and even fuzzy control. Furthermore, it can be and is applied to study traffic management measures, such as roundabouts, arterials, toll-plaza's, ramp metering, main-line metering, HOV lanes, tidal flow lanes, etc.

FLEXSYT-II runs on any PC with 4MB (preferably 8MB) of memory under MS-Windows. At this moment it can handle up to 10,000 vehicles, present in the network at the same time, but this number can easily be increased if more memory is available.

FLEXSYT-II (#FLEXSYT) by Henk Taale is available for $3000 at LOS 7. An educational version can be purchased for $25.

Workshop on Traffic Models in Support of IVHS Results report is a summary of the co-sponsored Federal Highway Administration (FHWA) and the Center of Microcomputers in Transportation (McTrans ) of the University of Florida. The workshop was held during the week of December 11-16, 1994 in St. Petersburg Beach, Florida. A total of fifty five traffic/transportation researchers, traffic model developers, users of traffic models and administrators of research programs on traffic models participated.

The propose of the workshop was to bring together designers, developers, and end users of the models and facilitate communications among these groups. These individuals came from the public sector, industry, and academia. The goal was to increase the understanding of the models and what is needed to make them more useful and used in support of traffic related activities.

This report, prepared by ANSTEC, Inc., summarizes the results of that meeting and is intended to provide recommendations for future work to increase the usability of the models. Section 2.0 describes the procedure followed during the meeting. Section 3.0 will provide a brief background into models and simulations Sections 4.0 and 5.0 will describe the results of two working group levels. Finally, Section 6.0 summarizes the overall conclusions developed during this workshop. A section containing attachments follows Section 6.0.

IVHS Workshop Results Report (#IVHSWS) is available for $5. The report is a hardcopy document.

CulvertMaster for Windows is Haestad Methods third addition to its family of object-oriented programs for civil engineers. This program designs and analyzes roadway and embankment culverts using the methodology found in the Federal Highway Administration's HDS #5 manual "Hydraulic Design of Highway Culverts". The program can model all standard sizes, shapes (circular, box, arch, and elliptical), and materials (concrete, CMP, plastic, and more). CulvertMaster easily models systems that include multiple barrels shapes and sizes set at different inverts, and automatically computes roadway and embankment overtopping. If you're tired of fighting HY-8 and HEC-2 when you need to analyze a culvert, then CulvertMaster is just what you're looking for. The program checks both inlet and outlet control and can display all results graphically in a rating curve or generate report-ready tabular output and rating tables. CulvertMaster's FlexUnits allows the user complete control over decimal precision and provides the ability to "mix and match" English and metric units in the input and output.

All of these features are packaged in a program that supports Windows 3.1, Windows 95, and Windows NT. CulvertMaster (like all Haestad Methods programs) includes unlimited, lifetime technical support directly from the developer. Further information is available via the Internet at http//:www.haestad.com.

CulvertMaster, (#CULVMSTR.WIN) by Haestad Methods Inc. is available for $495 at LOS 7.

CYBERNET is an AutoCAD-based water distribution network model that allows you to construct a pressure system graphically and then solve the hydraulics using the embedded KYPIPE-3 algorithms. CYBERNET's graphical modeling technology has proven to substantially reduce man-hours required to produce a finished analysis and greatly enhance the interpretation and presentation of model results.

With CYBERNET you visually lay out the network - element by element. You add new pipes and insert tanks, check valves, pumps, regulating valves, flow meters, and other system components to build a precisely scaled system map or even a simple network schematic. This graphical network "picture" is then solved automatically to compute pressures, flows, and hydraulic grades at locations throughout the system. The results can then be displayed graphically with contours, profiles, graphs, and color-coded mapping.

CYBERNET also computes available fire flows on a system-wide basis. Available fire flows can also be displayed with a contour map covering the entire service area. CYBERNET's built in source identification module will compute water age and simultaneously determine the source fractions or percentage flow contributions from all supply sources in the system.

CYBERNET runs inside of AutoCAD (versions 11, 12, 13) and can import data from most other water distribution programs. Further information and a free demo are available via the Internet at http//:www.haestad.com. Haestad Methods offers training courses on water distribution modeling using CYBERNET eight times a year across the United States. Please call 1-800-727-6555 for a schedule of courses near you.

CYBERNET Ver. 2.18, (#CYBERNET) by Haestad Methods Inc. is available for $195 at LOS7.

Quick Pipe PRO

The advanced professional version of Quick Pipe. The program allows for the analysis and design of highway drainage culverts using FHWA Hydraulic Design Series No. 5 procedures. Quick Pipe PRO will analyze over 700 predefined culvert shapes and sizes and includes: FULL METRIC SUPPORT, detailed tailwater channel analysis, and roadway overtopping analysis. The program features a windows type interface with a main menu bar and pull-down, easy data entry forms. The user interface supports the use of a mouse.

Quick Pipe PRO eliminates the use of standard culvert nomographs and uses well documented hydraulics methods and equations, which are discussed in the users manual, to compute inlet and outlet control for the following culvert shapes: round, metal and concrete box, pipe arch, ellipse, single radius arch, and low and high profile arches. Culverts are analyzed for both inlet and outlet control under a wide range of flow conditions. The program supports multiple cell analysis and will analyze scour potential at the culvert outlet. Metric input and output is supported, and you can switch between the two units at anytime during the analysis with the simple click of a mouse button.

Quick Pipe PRO will run under all operating systems designed for Intel microprocessors, including Windows 3.1/95/NT, OS/2, and DOS. All data input takes place in five entry forms (Site, Culvert, Flow, Tailwater, and Overtopping); culvert data is listed on FHWA's familiar culvert design screen. Data can also be saved to a culvert design file. Headwater calculation results can be printed to a text or graphics printer, a disk file, or copied to the Windows clipboard. On-line help is accessible from the menu bar and can be printed for inclusion in design reports.

The program supports both HP LaserJet and dot matrix printers and high quality headwater and tailwater culvert performance curves can also be viewed and printed, as well as the tailwater cross-section and roadway profile. Quick Pipe PRO comes with an extensive users quide that fully describes all program features and includes a discussion on culvert theory with example problems.

Quick Pipe PRO will operate with an IBM PC, and 640k of memory. A graphics printer and co-processor is recommended.

Quick Pipe PRO, Version 1.0 (#QPP) by C. Kirk Cover is available for $375 at LOS 6.

The Traffic Models Overview Handbook (TMOH) provides an overview of a number of Traffic Models for performing traffic signal timing optimization mainly for arterials and networks and for performing evaluations of traffic operations and geometric design plans for intersections, arterials, urban street networks, and freeways using simulation models. The simulation models reviewed encompass both macroscopic and microscopic models. The traffic models reviewed include: PASSER II, TRANSYT-7F, TRAF-NETSIM, CORFLO (NETFLO 1 &2 and FREFLO), FRESIM, ROADSIM, PASSER III, MAXBAND, SOAP, TIMACS, and FREQ. The purpose of the Handbook is to provide the transportation professional with information sufficient for deciding if a particular traffic model would be suitable for their applications and an idea on how much effort and resources would be required to apply the model effectively.

Appendices contain "Selected Traffic Model Inputs and Outputs", "Traffic Model Summary Comparison Tables," "Traffic Model Specific References", "Traffic Modelling References", and "Traffic Model References and Abstracts".

Traffic Models Overview Handbook (#TMOH) by FHWA (Contact: Ron Giguere) is available for $20. This is a hard document.

FlowMaster PE for Windows is an easy to use program for computing hydraulic properties of pipes, ditches, and natural channels. FlowMaster PE analyzes both pressure flow and open channel flow in pipes using Mannings, Kutters, Hazen-Williams, and the Darcy-Weisbach equations. Output for pressure pipes includes velocity, head loss, friction slope, energy grades, and more. Open channel output includes flow area, wetted perimeter, velocity, Froude number, critical depth and slope, top width, and other variables. Flowmaster PE can also develop rating tables and graphs, and includes the new FlexUnitsa option which gives the user total control of decimal precision and units. You can easily mix and match English and metric units (i.e. specify flow rate in cfs, and get velocity in meters per second).

The program easily analyzes circular and box pipes, man-made (triangular, trapazoidal, and rectangular) and natural (irregular) channels. All of these features are packaged in a program that supports Windows 3.1, Windows 95, and Windows NT. Further information is available via the Internet at http//:www.haestad.com.

FlowMaster, (#FLOWPE.WIN) by Haestad Methods Inc. is available for $195 at LOS 7.

StormCAD is a new Windows-based program for storm sewer design and analysis. StormCAD's "Point and Click" graphical network editor allows you to insert, drag, move, and label all elements in the scaleable, stand-alone StormCAD Windows environment, and is compatible with all major CAD applications (including AutoCAD, AutoCAD LT, Microstation, and GenericCADD). StormCAD's FlexUnits offer the user complete control over all input and output, including English/metric units and decimal precision.

The program can automatically determine pipe sizes and set inverts in its constraint based design mode. A user enters design parameters such as minimum and maximum allowable velocity, slope and cover, and the program sizes all pipes and calculates hydraulic grades throughout the system. The hydraulic algorithms can handle pressurized and free surface flow (for circular, box, elliptical, and arch pipes), adverse slopes, and junction losses using AASHTO methods. Tabular output can be customized to conform to your local agency's format - you pick what variables you want and the order they appear in. The WYSIWYG Plan and Profile graphics can be printed to any type of printer/plotter or saved to DXF files for use in construction drawings.

All of these features are packaged in a program that supports Windows 3.1, Windows 95, and Windows NT. StormCAD (like all Haestad Methods programs) includes unlimited, lifetime technical support directly from the developer. Further information is available via the Internet at http//:www.haestad.com.

StormCAD, (#StormCAD.WIN) by Haestad Methods Inc. is available for $495 at LOS 7.