McTrans Newsletter
March, 1996

10 Years and Growing

McTrans is coming up on its 10-year anniversary this summer. As part of this celebration, we are looking for feedback on our services and support. We know how surveys usually go, so we've decided to offer an incentive for you to respond. We are treating this survey as an entry form. Returning a completed survey automatically makes you eligible for $1,000 of free software to be given away to the lucky winner. Only survey respondents will be included in the drawing. You can print the survey form, circle your responses and fax it to (352) 392-3224 with your name, address and telephone number.

Please respond to the following statements by rating your experiences to the scale below:

1.When I call, I am promptly connected to the right person who can answer my questions.
5 4 3 2 1 0

2. When I place an order, it is processed and delivered accurately and quickly.
5 4 3 2 1 0

3. I find it convenient to contact McTrans through the 800 number, fax and/or e-mail.
5 4 3 2 1 0

4. The World Wide Web homepage is convenient and useful.
5 4 3 2 1 0

5. The technical assistance I receive is informed, helpful and responsive.
5 4 3 2 1 0

6. Upgrades, updates and patches to maintained software are timely and accurate.
5 4 3 2 1 0

7. I find the newsletter interesting and informative.
5 4 3 2 1 0

8. The catalog is well organized and a useful resource.
5 4 3 2 1 0

9. I find the McFinder useful.
5 4 3 2 1 0

10.I would like an on-line catalog and ordering.
5 4 3 2 1 0

11.I purchase most of my transportation related software from McTrans.
5 4 3 2 1 0

HCS News

Since the formal release of the Highway Capacity Software (HCS) release 2 incorporating the changes stipulated in the 1994 Update to the Highway Capacity Manual (HCM), there have been two patches issued. These interim patches have been an effort by McTrans to take advantage of the emerging electronic communication capabilities to get fixes into the hands of users more quickly, ahead of a formal update.

These interim patches have been made available for downloading from the McTrans bulletin board, McLink, and from the McTrans World Wide Web Homepage. Users have been notified through the newsletter in articles and using the "Update Watch" column, as well as in bulletins on McLink and the McTran web page. We have adopted this method of expediting delivery of interim patches in advance of an official update as used throughout the software industry.

Patch "c" of the HCS is being tested and will be available very soon. This patch is cumulative of all changes made since the official release. Since this is the final patch planned prior to a formal update, a notice is being sent to all HCS registered users with instructions on how to obtain the patch electronically, or on disk through the mail. A formal update to release 2.5 is scheduled for distribution this summer and will be sent automatically to all registered users.

HEC River Analysis System (HEC-RAS)

by

Gary Brunner, Senior Engineer, and Vernon Bonner, Chief

Hydrologic Engineering Center, Training Division

The Hydrologic Engineering Center (HEC) has developed the next generation software for one-dimensional river hydraulics. The HEC-RAS River Analysis System is the successor to the HEC-2 Water Surface Profiles Program, as well as providing unsteady flow, sediment transport, and hydraulic design capabilities. A common data representation of a river network is used by all modeling methods, thus allowing the user to more easily migrate from steady-flow to other one-dimensional flow calculations. The concept also provides a consistent usage of data among the modeling methods. The HEC-RAS program provides a steady-flow model with several significant advances over HEC-2. An overview of the program package and some of the improved hydraulic features are presented below.

HEC-RAS Overview

The HEC-RAS is an integrated package, designed for interactive use in a multi-tasking environment. The system uses a Graphical User Interface (GUI) for file management, data entry and editing, program execution, and output display. The system is designed to provide one-dimensional river modeling using steady-flow, unsteady-flow and sediment-transport computations based on a single geometric representation of the river network. The first release provides steady-flow, sub-critical, supercritical, and mixed-flow regime profile calculations for a river network.

The program has been developed based on a single definition of the river geometric data for all modeling methods. The five steps for developing a hydraulic model are: 1) Create a project file, 2) Develop the river network and enter geometric data, 3) Define flow and boundary conditions, 4) Perform hydraulic analyses, and 5) Review results and produce reports.

A Project File is a set of data files associated with a particular river system. Within a project, Plans can be developed from combinations of geometric and flow data, plus boundary conditions and run specifications. All input and output data for a plan are linked and assembled by the file manager.

River Networks are defined by drawing, with a mouse, a schematic of the river reaches from upstream to downstream, as shown in the Geometric Data Window in Figure 1. Each River

Reach is identified by a name. As reaches are connected together, Junctions are automatically formed. Junctions are also identified by name. After the network is defined, reach and junction input data can be entered. The data editors can be called by pressing the appropriate buttons on the right of the Geometric Data Window. Or, reach data can be imported from existing HEC-2 data sets.

Junctions are created in the network when reaches combine or divide. The junction is treated as a separate model element; either energy or momentum-based calculations can be performed at the junctions. Energy calculations are based on a reach length between the reaches, the momentum calculation also requires the angle of approach for the reach.

Cross sections are located by the reach name and river station. Pressing the cross-section icon provides the data entry editor. Data are defined by station-elevation coordinates, up to 500 coordinates are allowed. There is no maximum number of cross sections. The section data are stored in a downstream order based on their river-station number. Cross sections can be easily added or modified in any order. Cut, paste, and copy features are provided, along with separate expansion or contraction of the cross-section elements of overbanks and channel. Cross-section interpolation is provided using cross section coordinates. The program connects adjacent cross sections with chords at the boundaries, bank stations, and minimum point, The user can add chords graphically. The interpolated sections are marked in all displays to differentiate them from input data.

Steady-flow data are defined for the reach at any cross-section location. Multiple-profile calculations are supported. The boundary conditions are defined at downstream, and/or upstream ends of reaches depending on flow regime. Internal boundary conditions are defined by the junctions. The HEC-2 options for starting profile calculations are all supported.

Profile calculations are performed using the standard step-up procedure. Overbank conveyance is computed incrementally at coordinate points (HEC-2 style) or breaks in roughness (HEC-RAS default). Subcritical, supercritical, and mixed-flow profile calculations can be performed. The critical-depth routine searches the entire range of depths and locates multiple minima. The transition between supercritical and subcritical flow is determined based on momentum calculations. Detailed hydraulic jump location and losses are not computed; however, the jump location is defined between two cross sections.

Tabular output is available using pre-defined and user-defined tables. Cross-section tables provide detailed hydraulic information at a single location, for a profile. Up and down arrow buttons allow the user to page through the output or select specific cross sections. Profile tables provide summary information for all cross sections and profiles. Several pre-defined summary tables are available for the cross section, bridge, and culvert computations. User-defined tables can be developed from a menu of 120 output variables. Selected variables can be stored and recalled like pre-defined tables.

Graphical displays are available for cross sections, profiles, rating curves, and a X-Y-Z perspective plot of the river reach. The geometric data can be displayed from the View option, provided in most of the data-input editors. Computed results can be shown in all the graphical displays, from the View menu on the HEC-RAS Main Window. User control is provided for variables to plot, line color, width and type, plus axis labels and scale. The user can also zoom in on selected portions of the display, and zoom-out to the original size. All graphics are in vector form using calls to the Window'sTM Graphics Device Interface. Graphics can be sent to output devices through the Window's print manager, or they can be written to a meta file or sent to the Window's clip board.

Documentation includes a User's Manual and a Hydraulic Reference Manual, plus an Application Reference document is planned. The User's Manual provides: installation instructions; a program overview; an example application; file management; data entry; performing steady flow analysis; and viewing results. The Hydraulic Reference Manual provides: the theoretical basis for profile calculations; data requirements; optional capabilities; modeling bridges, culverts, and multiple openings; and floodway computations.

Version 1.1 Update

Since the first release of the HEC-RAS software, several minor bugs have been found and fixed. In addition to fixing bugs, a few new features have been added and some modifications to existing features. The software has been thoroughly tested under the Windows 95 operating system and the HEC-RAS software is now compatible with Microsoft Windows 3.1, 3.11, Windows NT 3.5 & 3.51, and Windows 85. There will be no release of the user's manuals with this version.

Acknowledgement

This paper includes the work of several colleagues, including: Mark Jenson, Co-Op Student, who was responsible for the HEC-RAS GUI and graphics, and Steven Piper, Hydraulic Engineer, who developed major portions of the new program code. Model testing with HEC-2 was performed by Ken Yokoyama, and the bridge analyses were performed by Mr. John Hunt; both were student interns from UC Davis. Mr. Gary Brunner is team leader for this project.

Design and Optimization Strategies for Traffic-Actuated Signal Timing Parameters

By David Hale, University of Florida

Traffic-actuated control, because of its ability to respond to fluctuations in traffic volumes, has gradually replaced pretimed control at most signalized intersections in the U.S.A. By employing more intelligent strategies than a pretimed controller would, traffic-actuated control is able to achieve significant savings in motorist operating costs. Despite the added efficiency that has been achieved through the deployment of traffic-actuated controllers, the prevailing lack of optimization of its operating parameters continues to impede the realization of substantial additional savings. Traffic engineering literature fails to recognize any single method as the best strategy for traffic-actuated control parameter design and optimization. While many independent methods do exist, they do not recognize the other methods for comparison, and they give little information pertaining to the degree of optimization that is achieved through the use of that particular method. The objectives of this study are to identifiy the control parameters that have the most significant influence on the performance of a traffic-actuated signal, and to determine which design and optimization methods from the literature are the most consistent. Since basic actuated controllers are the most commonly deployed, their operation is the focus of this study.

The detector configuration is typically 20-30 foot long inductive loops, called presence detectors, deployed at the stop bar of an intersection. The minimum green time must elapse before any given phase may be eligible for termination. The unit extension setting is the amount of time in which a detector must sense no vehicles above it before it decides to terminate the phase via gap out. In other words, the controller is searching for a certain sized gap in the traffic stream. If a phase does not gap out by the time the maximum green time has elapsed, the phase will terminate via max out.

Several methods for the design of the unit extension setting exist in the literature. The methods which correspond with basic actuated control are simple recommendations of a specific value or a narrow range within 0 and 4 seconds. Since basic actuated unit extension settings are typically designed with such a narrow range, individual jurisdictions would most likely implement nearly identical settings for identical field conditions in the absence of any recognized guidelines. This uniformity contrasts sharply with practices regarding the design of the maximum green setting. Chances are that two individual jurisdictions would come up with distinctly different maximum green setting designs if presented with the same field conditions at an intersection. The proliferation of their design and optimization methods which exist in the literature are a microcosm of this condition.

The "Target v/c" method for the design of maximum green, described in the Methodology for Optimizing Signal Timing (MOST) manual (3), can be applied through the WHICH program. Lin's method (4) performs calculation of the maximum green setting as a function of the peak hour factor and the optimal pretimed green setting. Portions of the "Overflow" method (5, 6) resemble a term from Webster's delay equation. EVIPAS (Enhanced Value Iteration Program for Actuated Signals) is a program which has the ability to optimize pretimed or traffic-actuated signal settings by performing large quantities of iterative simulation runs.

The results produced by exhaustive simulation runs using the TRAF-NETSIM program illustrate that the maximum green setting has a noticeable impact upon vehicle delay when traffic volumes approach or exceed the capacity of the lanes governed by the given phase. On the other hand, the next graph illustrates that an optimized unit extension setting would probably reduce vehicle delay by a relatively small amount.

These results indicate that the maximum green setting can and should be optimized. The model comparison analysis described henceforth involved the simulation of maximum green settings generated by the previously described methods to be used with eleven intersections from the Highway Capacity Manual's supplementary database of sample intersections. The method for design of the unit extension setting developed by Courage and Luh (8) was chosen to generate settings to be held constant while the maximum green setting was varied by method. EVIPAS was tested in the model comparison analysis using its own internally optimized unit extension settings as well as with those generated by Courage and Luh's method. The maximum green settings generated by Lin's method, as an example of the results, produced 7.1% higher stopped delay per vehicle when implemented in the HCM Chapter 9 database simulations than did the EVIPAS program with its own unit extension setting (Full EVIPAS). The root mean square (RMS) results were intended to highlight the erratic methods by giving significant weighting to the largest deviations from the optimum.

The comparison of computational models produces evidence that the EVIPAS program is the most accurate method for optimization of the maximum green setting, and its optimized maximums combined with its optimized unit extension settings produce even better results. The optimization methods referred to in this study could be used in conjunction with existing methods for pretimed signal setting optimization. The pretimed splits and offsets for the coordinated phases could be optimized with existing software. Subsequently, these previously optimized splits could be coded into EVIPAS and held constant in the iterative simulation runs to achieve optimization of the uncoordinated, traffic-actuated phases. Any pretimed phases which are not part of a coordinated system and that could not be re-designed as traffic-actuated phases could be optimized with EVIPAS as well.

Intersection Full Partial

File	EVIPAS	EVIPAS	Lin	Overflow	Target v/c
Name

H1	20.19	26.68	22.13	24.13		27.16

H2	14.47	15.24	15.95	14.48		17.21

H3	18.81	18.60	26.90	34.94		34.94

H4	37.08	38.88	39.48	39.98		39.42

S1	18.77	14.59	21.37	17.52		17.35

S3	22.00	23.08	31.10	28.94		26.51

S4	47.62	52.69	40.36	40.65		35.01

S5	15.74	16.75	25.02	16.29		16.75

F2	12.60	13.33	13.43	13.43		13.04

H5	42.00	40.88	39.01	40.49		37.35

S2	17.50	17.46	16.69	16.32		40.72

Avg. 	27.24	28.54	29.17	29.45		30.19
Delay1

% From 	0.0	4.8	7.1	8.1		10.8
Opt2
RMS3	4.22	5.71	5.14 	5.75		9.54

1 volume-weighted average stopped delay per vehicle, in units of seconds per vehicle

2 percent above the optimum average stopped delay per vehicle for the given sample intersection

3 root mean square term, in units of seconds per vehicle

1. Transportation Research Board, "Highway Capacity Manual", Special Report 209, Washignton, D.C., 1994.

2. "Capacity Analysis of Traffic-Actuated Intersections", NCHRP Project 3-48, Quarterly Progress Report, May 1995.

3. Courage, K. G. and C. E. Wallace, "Methodology for Optimizing Signal Timing: MOST Volume One", Gainesville, December 1991.

4. Lin, Feng-Bor. "Optimal Timing Setting and Detector Lengths of Presence Mode Full-Actuated Control". Transportation Research Record 1010, TRB, National Research Council, Washington D.C., 1985, pp. 37-45.

5. Skabardonis, A. "Progression Through a Series of Intersections with Traffic-Actuated Controllers", Final Report, FHWA Contract DTFH61-87-R-00027, 1988.

6. Fambro, D. B., Sunkari, S. R., Hubbard, S. M., and Irvine, Y. D. "Implementation Guidelines for Retiming Isolated Intersections", Report No. FHWA/TX-93/1164-1, Texas Transportation Institute, December 1992.

7. Bullen, A. G. R., N. Hummon, T. Bryer, and R. Nekmat, "EVIPAS: A Computer Model for the Optimal Design of a Vehicle-Actuated Traffic Signal", Transportation Research Record 1114, TRB, National Research Council, Washington, D. C., 1987, p. 106.

8. Courage, K. G. and J. Z. Luh, "Development of Guidelines for Implementing Computerized Timing Designs at Traffic-Actuated Signals", Gainesville, February, 1989.

New Products

Advanced Traffic Analysis CD

We have just received this self-running CD demonstration from FHWA which produces a multimedia presentation. It is designed to raise awareness and encourage the use of USDOT-sponsored research in traffic analysis. The CD will provide transportation officials, traffic engineers, urban planners and civic leaders with an automated presentation of advance traffic analysis technologies developed through FHWA.

Included in the presentation are demonstrations of the effectiveness of traffic analysis using such models as TRANSYT-7F, PASSER II-90, the Arterial Analysis Package (AAP) and TRAF-NETSIM.

Before ordering, please confirm that your system meets or exceeds the following requirements:

At least 8MB of RAM;

Hard disk with at least 15MB of available disk space;

Highcolor VGA display (16-bit and 65K colors);

CD-ROM drive (double speed, 300Kbs);

Audio board with headphones or speakers recommended;

Microsoft Windows 3.1; and

Windows-compatible mouse.

Especially note that the CD-ROM drive must be at least double speed and the VGA display must be capable of and configured for highcolor (65,000 colors).

The CD (#TRAFFIC.CD) is free, but orders must include the normal processing fee.

CD-ROUTE

PIARC has compiled on one support CD-ROM, (Macintosh©, PowerMac® and PC compatible) the unabridged version in English and French of its main and most recent reports, representing in total 8,000 pages approximately. The areas covered are:

road terminology

road policies

economics and finance

safety

environment

traffic

urban areas

interurban areas

materials and tests

earthworks and pavements

road bridges and tunnels

road maintenance, operation and maintenance

technology transfer

information about PIARC

the Technical Directory of Road Terms (English-French-Spanish)

the PIARC Lexicon (12,000 words or expressions in English-French)

the reports and proceedings of the XIXth World Road Congress in Marrakech (1991)

the 21 reports of Committees and Groups to the XXth World Road Congress in Montréal

many inter-congress reports

selected articles from <Routes/Roads>

a catalogue of the recent publications of the OECD Road Research Program.

PIARC CD-ROM (#PIARC.CD) is offered at LOS 5 for $200.

E-Z Signals

EzSignals was designed to work as a shell on top of HCS Signals to further enhance its features and capabilities. HCS Signals has long been one of the most widely used software packages among the transportation engineering professionals. Although its most recent release 2.4 has added many features, its user interface has remained literally unchanged in recent years. The Windows® interface makeover for HCS Signals is a giant step toward providing an easier and more functional environment for an already popular signal analysis tool. Since a typical transportation professional today is already using HCS Signalsperhaps even for yearsthis design philosophy not only allows you to keep your existing investment, but it also provides added features not found in HCS Signals.

We also envision EzSignals to be a 'plug-and-play' software with a wide range of add-on enhancement modules that you can choose for your own needs, such as graphical output, signal timing and phasing optimization, automatic generation of input files for other programs such as TRAF-NETSIM. The birth of EzSignals kicks off a new wave of traffic engineering analysis tools that are highly intuitive, user-friendly, flexible and expandable.

In addition to making use of basic Windows® interface, EzSignals sports the following enhanced features to the existing HCS Signals:

Point-and-click data entry

Drag-and-drop intersection layout

Multiple time period support

Hypertext on-line user guide and on-line help

Enhanced reporting

Planned add-on modules

EzSignals (#EZSIGNAL), Version 2.4a, by Viggen Corporation is available at LOS 7 for $95.

PONDS

PONDS is an interactive, menu-driven ground water-surface water computer program which was written specifically for analyzing stormwater management and percolation ponds. Interactive graphical and text help screens are provided in all modules. Although there are numerous other engineering applications for the generic modules, they have been tailored to perform design calculations for most of the typical stormwater management systems permitted in the state of Florida.

The methodologies in the PONDS computer program are formally approved by the St. Johns River Water Management District (F1) and the program is also used by the Southwest Florida Florida Water Management District (F1) for permit review purposes.

The program presently has seven (7) modules or menu options. Brief descriptions of the capabilities and applications of each of these modules are described in the following subsections.

Module #1: Retention Pond Recovery Analysis-Simplified Method

This method calculates the time for recovery of 1) dry bottom wet bottom retention ponds, 2) exfiltration trenches, and 3) swales following a slug or instantaneous filling of the pond. Typical water management district permit criteria require that the water quality (aka pollution abatement or treatment) volume instantaneously fill the pond without credit for ground infiltration during the filling of the pond.

Module #2: Retention Pond Recovery Analysis-Refined Method

This is the most powerful module in the PONDS computer program. It is a true ground water/surface water interaction MODFLOW-based model which simultaneously computes ground water and surface water discharges during and following transient hydraulic (hydrograph) loading of a stormwater pond. The groundwater component can be deactivated by using a low soil permeability in the routing analysis.

To the author's knowledge, there is no commercially available computer program which has the true ground water/surface water interaction modeling capabilities of the Retention Poind Recovery Analysis-Refined Method module.

Module #3: SCS Unit Hydrograph Generation Routine

This module generates SCS unit hydrographs which can be imported into Module #2.

Module #4: Ground Water Baseflow (or Background Seepage) Calculations

This module calculates the peak ground water baseflow into retention and wet detention ponds in water table (unconfined) aquifers which have their control elevations set below the seasonal high water table. A by-product of this MODFLOW analysis is the induced draw down of the water table as a function of distance from the edge of the pond. This module has a multitude of other applications including the ability to simulate borrow pit dewatering and ground water seepage into roadway underdrains, ditches, interceptor trenches, etc. It is also useful for assessing potential wetland deydration impacts.

Module #5: Calculation of the Length of Side-Bank & Bottom Filter

This module calculates the length of side-bank or pond-bottom drain filter required for retention ponds that treat stormwater with filtration systems.

Module #6: Vertical Volume Recovery (Filtration) Structures (aka VVRSs)

This module computes the number of Vertical Hollow Cylindrical Sand Filters (also known as Vertical Volume Recovery Structures or VVRS) required for recovery of the treatment volume.

Module #7: Underdrain Design Calculations

This module determines the spacing, total length, and diameter of subsurface drains for "Underdrained Retention Ponds", a relatively new but increasingly popular stormwater best management practice in Florida.

Ground water baseflow (computed in Module #4) can be automatically included in Modules #5, #6, and #7.

PONDS (#PONDS) by Devo Seereeram, is available for $700 at LOS 7. Multiple copy discounts are available.

SIG/Cinema 1.0, developed by KLD Associates and the Polytechnic University, implements a signal optimization capability for isolated intersections which provides: 1) optimal signal phasing sequence; and 2) optimal signal timing for each candidate signal phasing combination. It retains the popular graphics user interface (GUI) of HCM/Cinema, including interactive displays of the intersection configuration; signal phasing diagrams; NETSIM® simulation of traffic operations; and graphical animation of vehicle movements.

A unique feature of SIG/Cinema enables the user to select the most attractive optimization objective from among five offered: 1) Equilibrate V/C ratios among the critical lane movements; 2) Equilibrate delay per vehicle among the critical lane movements; 3) Equilibrate delay per vehicle among all approaches, over all movements; 4) Minimize total intersection delay with no consideration of equity of service among the competing traffic streams; 5) Minimize total intersection delay subject to satisfying specified minimal thresholds of level of service (LOS) for each approach. Each of the first three objectives allocates service "equitably" so that all travelers experience a comparable LOS at the intersection. The fourth objective minimizes overall vehicle delay with not consideration of service equity. The fifth objective strikes a balance between minimizing intersection delay and providing equity of service. Here, the optimization minimizes intersection delay subject to satisfying a user-specified level of service for each approach.

The software package up to five "default" signal phasing sequences in each direction, yielding a total of up to 25 signal phasing combinations for each selected objective. The user can also customize any phasing sequence, or any phase within a default sequence, to meet the specific needs of the intersection/traffic scenario. For each selected phasing combination, up to 12 cycle lengths can be investigated in any run. All signal timing solutions, along with their associated approach-specific LOS values, are presented on-screen so the user may interactively examine those which are most appealing, using the friendly menu structure to obtain the "best" solution in minutes. The associated HCM Ch. 9 intersection Capacity and LOS are provided along with the ability to print any screen and all results. The user can simulate and animate traffic movements for the resulting intersection design and control. SIG/Cinema 1.0 comes complete with illustrated Users Guide.

HCM/Cinema users--who total almost 2,000 copies--may upgrade to SIG/Cinema at a cost of $200, only from KLD Associates. Both products come with a 30-day money back guarantee.

SIG/CINEMA (#SIGCIN) by KLD Associates is available at LOS 7 for $805.

WINPROfile FOR '96

Now you can directly transfer complete grade, street, storm sewer, sanitary sewer, water line and other profiles to open Autocad® and Microstation® Files while in WINPROfile.

If desired, transfer may also be made using dxf files created inside WINPROfile.

All computational routines needed for normal street grade computations, storm drain sizing and profile preparation are merely a few key strokes away.

Transferred profile linework may be generated at user given vertical and horizontal scales. The transferred text data includes station, elevation, pipe capacity, actual flow, velocity, length, and slope.

WINPROfile is designed to allow generation of profiles from minimal input. A typical 1200' profile (30" long @ 1"=40') with storm sewer, water line, vertical curves, etc. can be input and transferred to CAD as a complete profile with all appropriate text in less than 20 minutes.< /FONT>

If pipe flows are known, pipe sizes will be computed using that flow. If pipe sizes are known, the flow for that pipe size is computed. This is true for either sewer or storm sewer lines. Top of frame elevations for inlets are computed at the given vertical offset from street grade. Street grades are computed at 50' stationing on tangents and 25' on vertical curves.

Complete vertical curve data is shown in the generated CAD or DXF file. The pipe data shown in the generated file consists of flow, slope, length, velocity, inverts, top of frames and stationing.

WINPROfile provides :

generation of CAD files of street profiles w/station & elevations on street tangent sections & vertical curves.

pipe sizes computed using Mannings formula.

tip of frames for inlets computed to match street grade with given grade differential.

preview of profile on video prior to transfer to the CAD system.

ease to use.