The Petersham Hole was a sink hole caused by subsidence of a sewer which forced the total closure of the A307 road in Petersham in 1979–80. As the hole and subsequent repair work had forced a total closure of this main road between Richmond and Kingston, traffic was diverted through the park and the Richmond, Ham, and Kingston gates remained open throughout the day and night. The park road was widened at Ham Cross near Ham Gate to accommodate temporary traffic lights. About 10 deer a month were killed by traffic while the diversion was in operation.