Witnesses on scene reportedly told police that an unidentified black car cut off the motorcycle causing it to travel into the shoulder.
The on ramp was closed for about three-and-a-half hours.
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The car did not strike the motorcycle and witnesses could not identify nor describe the driver, according to Maryland State Police.
Thompson was pronounced dead at the scene by Montgomery County EMS at approximately 6 p.m. The motorcyclist had a passenger who was taken to an area hospital with non-life-threatening injuries.