North Bethesda, Maryland Automated Microbus Application
The Grosvenor-Strathmore Metrorail station lies just outside the Washington, DC beltway in suburban Maryland, about two miles (3 km) from a large office park and regional mall. In 1992, the local planning agency commissioned a study to investigate using an advanced technology transit system to connect the rail station with the office park and mall. Although the study results were encouraging, no system has yet been implemented, and the only connection is by bus. The above diagram shows how an Automated Microbus system could connect the rail station to the office park and mall. More than half of the Microbus system runs at grade along two sections of an Interstate highway. Short branch lines bring the system into the office park without requiring elevated roadway.
The above aerial photo shows the Automated Microbus system in more detail. The width of the Microbus line is exaggerated in the small image on this page, but clicking on it brings up a 2000 by 750 pixel image that shows the line to scale. An even larger version is available here. For comparison, the route of an automated monorail alternative from the 1992 study is shown below.
To properly display Microbus system details, such as the center barrier between the two lanes, a higher resolution is desirable. This makes it difficult to show the entire system at one time. The image at the right gives a detailed view of just the western terminus, which would serve a regional mall. Five vehicles can be seen waiting at the station.
All Microbus trips would be non-stop, origin to destination. During peak periods, Microbuses are shared, while in the off peak vehicles are available on demand and most trips are single party. A surcharge for private service is possible. Stations use 45-degree, back-out docking, so all berths operate independently. Vehicle design and operating policies follow accepted APM standards. Acceleration and jerk limits are set for standees, although a low profile results in most passengers being seated.
The North Bethesda application is similar to the generic Beltway Shuttle concept, although it does not literally run along a beltway. The North Bethesda alignment is described in detail here. Four of the five stations are located at grade at the ends of short branch lines. It's estimated that because of the limited number of Microbus stations, an average vehicle occupancy of five passengers could be achieved for trips to and from the Metrorail station.
The 1992 study alternatives were estimated to cost between $64 million and $82 million in 1990 dollars, and carry between 11,000 and 14,000 daily passengers by the year 2020. They were expected to eliminate the need for 2,000 parking spaces. An Automated Microbus system appears to offer comparable peak period service, as well as better off-peak service, lower costs, and much lower visual impact.