Greenburgh Police said Tarrytown Road/Route 119 is closed to eastbound traffic at its intersection with Aqueduct Road.
Eastbound traffic is being detoured to Aqueduct Road and Old Kensico Road, Lt. Kobie Powell said.
Police are not sure how long the closure will be necessary.
Alternate routes should be utilized if possible.
Details on the extent of any injuries suffered by the pedestrian have not yet been released.
This is a developing story. Check back to Daily Voice for updates.
Click here to follow Daily Voice Armonk and receive free news updates.