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Speed Restrictions

A construction worker drives a piece of machinery over train tracks in a tunnel on the Blue Line. Other workers to the left and the right of the tracks watch as the machinery drives by.

What Is a Speed Restriction?

A speed restriction is an area in which trains are required to run at slower-than-normal speeds because of track wear and tear or other problems. Speed restrictions are put in place to ensure rider safety.

Line-wide speed restrictions apply across an entire line. Block speed restrictions are specific lengths of track that may include one or multiple defects that need to be investigated or mitigated. As each defect is validated and corrected, the length of the block restriction is reduced until the speed restriction is fully removed.

Track conditions that make slower speeds necessary can develop for several reasons, including age and weather. These sections of track are sometimes referred to as slow zones.

Clearing speed restrictions can involve different kinds of work, including:

  • Replacing aging rail ties and tie plates with new ones
  • Replacing the whole track
  • Improving power delivery systems

Track renewal work is an ongoing effort to remove and prevent speed restrictions on our rail system.

We’re addressing speed restrictions and other improvement areas as part of our response to the Federal Transit Authority’s (FTA) Safety Management Inspection and report. We’ve developed a series of Corrective Action Plans to meet FTA Special Directive 22-04: Track Maintenance & PPE.

Learn more about how we’re improving in response to the FTA report

Explore the Speed Restrictions Dashboard

Interact with the dashboard below to view information on speed restrictions. Data is updated every morning before the start of service with the previous day’s data. For real-time information, sign up for alerts.

This dashboard includes data from January 1, 2023 onward.

Performance Metrics

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How We Measure Speed Restrictions

Full-Service Speed

The planned speed at which vehicles can travel on a segment during normal operation, or the speed at which vehicles can travel on the segment without any speed restriction.

Restricted Distance

The distance between the start and end markers of the restriction, measured to the nearest hundredth of a mile.

Track Miles (Miles of Track)

Track miles refers to the total length of the line in both directions, measured to the nearest hundredth of a mile.

Restricted Track Percent

Sum length of restriction distance over total track miles.

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Performance Metrics

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Sign Up for Service Alerts

On the platform in Park Street Station, a woman holds her smartphone with a Green Line train in the background.

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