321 - Luton - Harpenden - St. Albans - Chiswell Green - Garston - Watford
Luton - Harpenden - St. Albans - Chiswell Green - Garston - Watford
Service 321 gives a half-hourly link on Mondays to Saturdays from Luton Airport to Watford, calling at Luton, Harpenden, St. Albans, Garston and Watford Junction on the way. Between Watford and St. Albans buses run every fifteen minutes. Buses also run hourly from Luton Airport to Watford on Sundays.