A pedestrian flow simulation model was developed to test and evaluate the proposed underground pedestrian network for Grand Central Terminal's North End Access Improvements. The simulation model runs on a personal computer (PC) using the LOTUS 1-2-3 spreadsheet program. Based on the results of the simulation, pl~ nners modified the design to increase the capacities of certain passageways and to develop a more cost-effective design solution. Also, the model was used to test nearly a dozen construction-phasing options to respond to capital funding availability and passenger flow needs. The model, although not as sophisticated as some previous simulation programs, proved to be a useful and costeffective tool in the design process. It uses widely available, inexpensive personal computer hardware and software. The pedestrian flow simulation model, its essential components, and how it was used as a design tool are described in this paper. The advantages and disadvantages of this type of approach are discussed in the conclusion.

The design of a new underground pedestrian passageway system is underway for historic Grand Central Terminal in New York City. Metro-North Commuter Railroad Corporation of the Metropolitan Transportation Authority is planning the North End Access Improvements to shorten the travel time for commuters and to reduce pedestrian congestion within and around the terminal. More than 150,000 rail commuters and subway riders will benefit from the improvements each day. A pedestrian flow simulation model that was developed to test and evaluate the proposed facilities is described in this paper. The simulation model runs on a personal computer (PC) using the LOTUS 1-2-3 spreadsheet program. Based on the results of the simulation, planners modified the design to increase capacities of passageways and to develop more costeffective design solutions. The model also was used to test nearly a dozen construction-phasing options to respond to capital funding availability and passenger flow needs.