Transbay Terminal Case Study

The design for a new Transbay Terminal in San Francisco needed to demonstrate effectiveness in three key areas of pedestrian activity:

  • Transit boardings and alightings
  • Interchange between transit modes
  • Neighbourhood impacts

The new terminal will be a multi-modal transit hub designed to serve commuter rail, commuter bus, local bus, and eventually high speed rail passengers in downtown San Francisco. The variety of modes, degree of interchange between modes, and density of the surrounding urban fabric required an analysis approach that would consider the interaction of people with disparate destinations and patterns of movement within a complex environment. MassMotion models were constructed to assist the design team in analyzing the proposed layout of the station. The intended use of the model was to predict:

  • Capacity of platforms and vertical circulation
  • Demand on internal circulation routes
  • Neighbourhood dispersion patterns

Results
The simulation results indicated that early designs of the terminal building contained problem areas from a pedestrian circulation point of view due to insufficient channel widths in what were predicted to be high volume routes. Subsequent design iterations contained changes which eliminated areas of congestion according to the simulation results. At the end of schematic design the simulations were predicting that there would be no significant concerns regarding the boarding and alighting of passengers, that the internal circulation of the terminal building would accommodate projected traffic, and that there would not be significant impact to neighbourhood sidewalks.

MassMotion screen capture of running simulation including average crowd density mapping

It is clear from the Transbay case study that a simulation tool that minimizes the amount of modeler effort and provides a predictive view of design effectiveness is exceptionally valuable to the planning and design process. It enables the design team to devote less time to modeling more time to analysis and alternatives exploration which in turn increases confidence in the effectiveness of the design.

In addition to providing the design team with analysis of particular conditions and comparisons with desired outcomes it turns out that there are significant communications advantages to the MassMotion system. During the design process it became standard practice to bring the simulation model to design meeting for on the spot querying of particular issues and to gain insight into the overall functioning of the pedestrian network. The 3D models and animated motion of the agents provided a clear depiction of projected conditions and in a number of cases eliminated extra design effort and construction expenses that might have been required without such a tool.

MassMotion Model - TransBat Terminal