The Tokyu Group of companies is one of the world's largest organisations with a turnover of more than 4000 bn YEN (£4bn). The group's activities are diverse, spanning more than 400 companies across both the manufacturing and non-manufacturing sectors. The Tokyu Research Institute operates as a central resource for all companies within the group, executing research projects on their behalf.

The Tokyu Research Institute have been using WITNESS to evaluate planning projects for the last three years. The company invested in WITNESS to help provide solutions in two main areas. Firstly, they wanted to use WITNESS to help improve environmental planning. With growing population density in urban areas, air and traffic pollution have become serious problems in Japan. It was recognised that if WITNESS could help to alleviate traffic problems, atmospheric conditions could be considerably improved. Secondly, the company felt that WITNESS could help to generally improve economic efficiency within the group of companies. Faced with the current economic recession, the need for Japanese companies to minimise wastage by improving efficiency is even more acute.

Designing a Car Park

The first project for which WITNESS was used was concerned with town planning. Tokyu were asked to simulate a car parking facility within an inner city planning programme. They were tasked with not only identifying how to best utilise space within the car park but also with how to minimise congestion both within the car park itself and its surrounding area.

Firstly Tokyu examined traffic flow into and out of the facility. WITNESS simulation can handle the variation in speed, destination and parking time of different drivers, thus ensuring that this model gave a true reflection of the real life variances in traffic flow around the car park. The model also included traffic control features such as traffic lights and pedestrian crossings, complete with pedestrians using this facility. Once Tokyu were confident that they had established a model which was representative of reality, they began to experiment with the model in order to identify the optimum route of cars travelling directly to and from the car park and consequently the best location for entrances and exits. The different scenarios were numerous; should a one-way system be in operation? On which side of the car park should the entrance be located (considering through traffic levels)? Should the entrance and exit be adjacent? Would traffic lights positively affect traffic flow?.

After conducting a series of "what-if?" experiments in order to answer these questions, the company identified that traffic congestion would be minimised by placing the entrance and exits on different streets to the south and east of the car park block as is shown is figure 1.

The second part of the project consisted of building a model to simulate the interior of the car park facility. Tokyu were able to vary the architectural design and the positioning of walls and pillars in order to arrive at the best solution. After undertaking considerable experimentation with the system, it was identified that in order to maximise space usage, the car park should be several storeys high and he parking of cars should be automatic, achieved via a set of lifts and transfer mechanisms.

Project Two: People Flow Model

The second model dealt with the flow of people within a shopping mall. The mall was a major development, consisting of 300 retail outlets covering 1.5km. WITNESS was used to ensure the most appropriate layout both in terms of safety and convenience. The model was substantial, dealing with up to 20,000 visitors at any one time. It traced the people density in different areas over time, highlighting congestion and safety issues. The number of customers in each shop was recorded very 3 minutes and the amount of time spent in each shop fell into once of 6 bands. The model also took into account walking speed, the direction and route that each visitor took. Tokyu experimented with the positioning of shops, seating and walkways etc and investigated the effect of such changes on congestion. As a result of experimentation, the organisation was able to identify serious layout problems and act accordingly. Special attention was given to health & safety issues e.g. were there enough safety exits, could people reach stairs quickly etc.

Part of this model also dealt with people flow through the adjoining train station. People were classified as slow, medium and fast walkers. At any one time up to 300 people were waiting to board a train. The model helped to identify how many gates were needed in the station, the optimum passage size, the size of train needed to fulfil demand, and the frequency of train arrivals. Tokyu believe that the improved planning resulting from this study will not only help to improve efficiency but will also considerable reduce the risk of disaster.