Green Line (operated by Arriva) operates a bus from Watford to Harefield every 30 minutes. Tickets cost $5 and the journey takes 25 min. 2 other operators also service this route.
How to get from Watford to Harefield
From Watford, Town Hall bus to Denham, Station Parade (Morten Gardens) then line 331 bus to Harefield, The Green Harefield. 38 min £5. From Watford, Beechen Grove line 8 bus to Northwood, Mount Vernon Hospital then bus to Harefield, The Green Harefield. 50 min £6. From Watford taxi to Harefield. 11 min £30. From Watford drive to Harefield. 11 min £1. From Watford walk to Harefield. 2 h 5 min.