Bay Area Rapid Transit (BART)

The Bay Area Rapid Transit system is a train network that serves the greater San Francisco area.

• BART goes from downtown to the airport, which is better than the majority of North American transit systems

Track Gauge

50 years of BART: Why BART uses a nonstandard broad gauge

The standard rail gauge is exactly four-feet-and-eight-and-a-half inches. That gauge is used across the world to connect rail systems together across cities, regions, and nations. BART famously uses a much broader gauge, at five-feet-six-inches long.

The pamphlet rests upon the conclusion that BART cars would be considerably more lightweight compared to similar vehicles. BART intentionally designed the cars to be lightweight. “The lighter the vehicle, the easier it will be to move it from a standstill to a high speed and to decelerate it smoothly,” the report explains.

With lightness comes certain challenges, however. On aerial trackways during high wind events – which the engineers knew were not uncommon in places such as Contra Costa County -- the light BART cars could potentially tip over, the engineers hypothesized.

• It appears that design documents don't explain why the 5'6" gauge was chosen over other wider guages.
• Aside from safety and energy concerns, how does the increased financial cost factor into using nonstandard gauge?
  • Does this increase repair times and costs?
  • Does this make expansion more difficult?

Michael Healy, a BART historian and the former BART Director of Public Affairs, believes the use of the broad gauge “goes back to when BART was planned to go across the lower deck of the Golden Gate Bridge,” he told BART recently.

Created 2024-06-24.

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