The Miasma Beach Transportation Model

Executive Summary
Tasks 1-6

prepared for
the City of Miasma Beach
by
123 Consulting, Inc., Irvine CA

June 1, 2024

This report summarizes model development and validation for the Miasma Beach Transportation Model, corresponding to Tasks 1 through 6. Tasks 1 and 2 were presented in the first Technical Report and are summarized herein only to provide a final network validation summary and the skim trees for Task 4.

Task 3 develops and applies linear regression models for trip productions and attractions for the defined trip purposes (HBW, HBO, and NHB), for the internal Miasma Beach zones. Attractions are balanced so that total attractions equals total productions. All models are statistically significant and reproduce base trip productions and attractions within acceptable tolerance. Task 4 involves the application of a previously calibrated doubly-constrained gravity model for trip distribution, as well as necessary matrix adjustments for PA-to-OD, time-of-day, and vehicle trip conversions. Task 5 involves incorporating external ODs in the base trip table and completing a User Equilibrium traffic assignment for the area. The overall model system was validated by comparing screenline volumes with observed counts in key areas of the City. All screenline differences were within 5 percent and thus acceptable. Summary performance measures (average speed and VMT) were computed to use as a base reference against future design alternatives in Task 6.
Task 6 involves the development and analysis of transportation alternatives for the 2030 forecast year for Miasma Beach, including network modeling, an assessment of how well identified transportation problems were addressed, and a full cost evaluation.