FitzHerbert and his wife, Kay, were hit by a car at 4.45pm on 7 January while crossing the A5 in the village of Weedon. They had just left their narrowboat on the nearby Grand Union Canal.
FitzHerbert, one of the voluntary sector's most prominent figures, died at the scene. His wife suffered serious leg injuries and is recovering in Northampton General Hospital.
The incident happened on a stretch of road which has seen five fatal accidents since October. Less than a month ago, 17-year-old Lee Hemmings was killed there.
Graham Smith, Conservative councillor for Heyford, said: "I've written to our local MP asking him to raise our concerns with the Highways Agency to get the speed limit reduced from 60 miles per hour to 50."
Northamptonshire police are investigating the accident.