The Miasma Beach Transportation Model

Tasks 1 and 2 serve to develop the Miasma Beach network and skim trees. The modeling approach is to calibrate and validate trip generation (Task 3) and trip distribution models (Task 4) for the six internal zones only. Time-of-day adjustments and interactions with the external area (via the external stations) are modeled prior to trip assignment (Task 5). Model validation is completed prior to starting Task 6, where independent forecasts of the future activity system are applied to the validated base Miasma Beach transportation model. An evaluation of anticipated network performance leads to the development and evaluation of future network alternatives (Task 6 and 7).

The following summary is extracted from the full Miasma Beach Request for Proposals (RFP) Tasks Description and is repeated here to emphasize these reporting requirements.

Task 1. VALIDATE 2020 BASE YEAR NETWORK

The purpose of Task 1 is to develop, enhance, and validate the base transportation network for Miasma Beach.

This task involves the development of the transportation network for Miasma Beach, including updating the Transportation and Activity systems and producing corresponding graphic and tabular summaries.

Please Note: The initial Miasma Beach data set provided does NOT represent the actual base network. The only networks and data sets depicted or provided are for the prior model for 2000 and the network that you will create for 2020 using the initial "MB-dataset.zip" and this year's instructions in Task 1.

Deliverables: Summarize the data base development and validation process and submit the validated base year TransCAD data set for Miasma Beach, including text, tabular, and graphical description.

Task 2. DEVELOP 2020 BASE YEAR TransCAD NETWORK AND SKIM TREES

The first objective of this task is to create a TransCAD network file to find skim trees for use in subsequent models.

Deliverable: Create the TransCAD *.NET file for Task 2 Skim Tree analysis. To be submitted as part of Interim Report 1.

The second objective of this task is to develop the base year skim trees for Miasma Beach. These serve in error checking the network and as input to subsequent model steps. Note: You can not proceed with other Tasks until you have verified that the network is correct.

Deliverable: Include graphical and tabular summaries of skim trees, with and without intrazonal and terminal times.

Task 3. DEMAND FORECASTING: TRIP GENERATION

The purpose of Task 3 is to develop and apply trip generation models for Miasma Beach.

Select Version:
After the City approves your work, each team will select one report and dataset on which to base all subsequent analysis. Each team member will work independently but with the same report and dataset.

3.1 Description of the Zoning System
Provide a description of the study area. You must convince the client that you know everything of importance about the Miasma Beach area. If you extract material from the RFP, be sure that it is properly quoted and referenced.

3.2 Development of Trip Production and Attraction Models
You will estimate trip generation models for a specified trip purpose, and use designated models for other trip purposes. You must clearly identify the final set of models and discuss/tabulate them. All statistical output must be provided in your report or appendices. All original work should reflect your firm name as part of displays. Apply your models to the base year data and compare projected Ps and As to the base values. Provide summary stats, tables, and discussion.

3.3 Trip Balancing
Balance internal Ps and As separately for EACH trip purposes. Provide summary tables.

3.4 Prepare Task 3 Documentation
Prepare a Task 3 Interim Report documenting all work in trip generation model development. Include all tables, network graphics, and other outputs in your report. Because each group uses different production models, do not expect your results to be the same as those for other groups. Include all regression analysis results in an appendix. Follow Report Format Guidelines in the preparation of this report. This report will be submitted as part of Interim Report 2 with the results of Tasks 4 and 5.

Deliverables: A detailed description of the study area; a summary of the development and validation process for trip generation (including a table summary of all models estimated and a table summary of all final models); and the results of trip balancing.

Task 4. DEMAND FORECASTING: TRIP DISTRIBUTION

The purpose of Task 4 is to apply and validate a calibrated gravity model for Miasma Beach.

4.1 Base Gravity Model Application
Apply the model to base year data for the six internal zones, for the three trip purposes. Summarize the model itself and the process of integrating the calibrated friction factors.

4.2 Applying the Gravity Model
Apply the model to the base year data for the six internal zones, for the three trip purposes. Provide summary results, including the PA tables for each purpose, and discussion of the validation.

4.3 Converting P-A to O-D and Time-of-Day Transformations
Convert each trip purpose PA matrix to the corresponding O/D matrix for the AM-peak hour (7-8 AM), reflecting vehicle occupancy. Also produce the total purpose file which combines all three trip purposes into an integrated trip table for traffic assignment. Provide summary results for each step, including the PA tables for each purpose, and discussion of model validation.

4.4 Interim Report
Prepare a Task 4 Interim Report documenting all work in trip distribution model development. Follow Report Format Guidelines in the preparation of this report. This report will be submitted as part of Interim Report 2 with the results of Tasks 3 and 5.

Deliverables: A discussion of the trip distribution model utilized, and a discussion of the trip generation - trip distribution connection; the results of model application to the base year data; and the results after all adjustments to the model (including PA-to-OD, ToD, and occupancy factoring).

Task 5. DEMAND FORECASTING: TRIP ASSIGNMENT

The purpose of Task 5 is to load the estimated AM-peak hour O/D vehicle trip table onto the base Miasma Beach network and to validate estimated link flows and travel times against observed flows provided.

5.1 External Station Trip Interchanges
Task 3 and 4 considered internal zones only (TAZ 1-6). A separate analysis of external trip generation and distribution is provided. Append these trips to the total purpose matrix to form the final assignment matrix.

5.2 User Equilibrium Assignment
Assign the base O/D matrix developed in Task 5.1 to your network via User Equilibrium Assignment (UE). Summarize the iterative procedure and it's convergence. Tabulate link performance results (such as volume/capacities or speed); plot directional volumes and performance data.

5.3 Model Validation
Compare your base assignment with the observed flow pattern provided. Construct a minimum of three screen lines across which total flows will be measured and compared. Provide screen line summary diagrams and tables, clearly identifying the screenlines and associated total volumes. Specify deviations between observed and estimated link volumes. Discuss the accuracy of your model system.

5.4 Model Validation Interim Report
Submit a Project Interim Report containing reports for Tasks 3 - 5 as well as model validation results. Identify any current network supply deficiencies or excessive demand patterns. This information should be presented in graphical, tabular, and text format. The network deficiencies will help you identify any current performance problems which may have to be remedied. The Generation of Alternate Solutions will be based on the future performance of the network (see Task 6). Follow Report Format Guidelines in the preparation of this report. This report will be submitted as part of Interim Report 2 with the results of Tasks 3 and 4.

Deliverables: A discussion of the external station adjustments; full discussion of the UE process and results; and an analysis and assessment of overall model valiadation. You must include the corrected Tasks 1 and 2 with Interim Report 2.

Typical Results:

Trip Generation:

1. Zonal number and percent of trips by purpose, and totals
2. Daily trips by purpose per person, per household, and per employee
3. Zonal household descriptors such as persons per HH, workers per HH, employees per population, etc.

Trip Distribution:

1. Average trip lengths by purpose
2. Trip length frequency distributions (tabular and graphed) by purpose
3. Difference between input and output trip attractions by zone
4. Number and percentage of interzonal and intrazonal trips by purpose

Time-of-Day:

1. Number and percentage of trips by purpose in period versus daily

Trip Assignment:

1. Vehicle-miles traveled (VMT)
2. Vehicle-hours traveled (VHT)
3. Number of trips loaded and counted
1. by screenline, cutline, and cordon line
2. By area type and facility (link) type
4. Input and congested speeds (and percent differences)

Task 6. DEMAND FORECASTING: FUTURE

The Task 6 objective is to apply the validated model system to the Miasma Beach activity system for 2030.

Select Version:
After the City approves your work, each team will select one report and dataset on which to base all subsequent analysis. Each team member will develop, analyze, evaluate, and document an independent design alterntive but the team will submit a single integrated Final Report.

6.1 Forecast Future Demand for Year 2030
Apply your base trip generation, trip distribution, trip table adjustments, and trip assignment models to the forecast 2030 activity system. Follow all the steps, and provide similar tables and discussion, as for the base model application. These are your regional forecasts corresponding to a "No Build" alterative (A0, no network improvements).

6.2 Develop Future Network Alternatives
Apply the Transportation Planning Process. Based on the results of Task 6.1, clearly define key anticiapted transportation problems in Miasma Beach. Identify and justify those future deficiencies which you believe to be most critical and proceed to develop alternate potential solutions to address these identified problem(s).

Each team will develop three independent future network alternatives (A1, A2, and A3), one per team member. Each of these alternatives will be fully described and modeled, with estimated performance improvements and associated costs.

6.3 Performance Measures
Propose, comput, tabulate, and discuss key performance measures for decision-makers. Measures may be system wide (e.g., total VMT, average speed), link or corridor level (e.g., VMT or speed by link type), or intersection specific (e.g., LOS).

6.4 Recommendations
Based on your assessment of the traffic modeling and cost estimates, justify a single recommendation to the Miasma Beach City Council. Provide supporting evidence in concise displays (graphs, tables, etc.). Only one alternative (A0, A1, A2, or A3) can be recommended.

No interim report. All results should be integrated into the final report (Task 7).

Task 7. FINAL REPORT

The purpose of Task 7 is to produce and submit a comprehensive final report for the entire Miasma Beach project (incorporating all corrections from prior tasks). Follow report format guidelines. in the preparation of this report. This team report will be submitted as the Final Project Report summarizing Tasks 1-7.