Proposed new date (This leg had to be postponed twice due to the expected high temperatures).

Car shares and a packed lunch will be needed for this walk.

We start by driving to the Longspring car park in North Watford (https://maps.app.goo.gl/7d9WSdKWaJg1X91VA, postcode WD24 6PX) arriving at 09:30 latest.  This car park has 80 spaces and it costs £3.20 to park all day.  Payment can be made by cash, card or RingGo (location 26791). 
Walk 0.1 miles, 3 mins approx., northeast up Longspring and then St. Albans Rd. to Bushey Mill Lane bus stop at https://maps.app.goo.gl/H4s7vx5yxyMf36Ue9.  At 09:44, catch the 321 bus towards Luton.

Alight from the 321 bus at Holywell Hill / St. Albans Abbey Station bus stop at https://maps.app.goo.gl/jLT4iJNcFR1hwrtbA in St. Albans at around 10:10.
Walk 0.1 miles (2 mins approx.) to Westminster Lodge Leisure Centre at https://maps.app.goo.gl/Wc6HvKyrruJKt3kq8 for pre-walk refreshments and toilets.

Leave the leisure centre between 10:45 and 11:00, and walk just over 4 miles (1½ hrs approx.) to Riverside Way Car Park and Picnic Area at https://maps.app.goo.gl/5jfW8rAfUYUf3TydA, arriving between 12:15 and 12:30, where we eat our packed lunches.  There should be a few suitable bushes and trees here for those in need.

Leave the picnic area at around 1:15 to 1:30 pm, walk another 4.3 miles (1¾ hrs approx.) to The Tudor Arms in North Watford at https://maps.app.goo.gl/hMngxdXxcC8gfiw76, arriving at around 3:00 to 3:15 pm, for end-of-walk refreshment and toilets.  Alternative refreshments and toilets should be available from The Tudor Café and Bistro directly opposite the Tudor Arms.

From the Tudor Arms it is then a 0.7 mile, 16 minute approx. walk northwest along Bushey Mill Lane, back to the Longspring car park.  Alternatively, catch a W1 or 635 bus (6 minute ride) from opposite the Tudor Arms, although these only run about once an hour.  There is a W1 at 3:58 pm.

The full route from St. Albans Abbey Station bus stop to The Tudor Arms in North Watford can be viewed at https://www.mappedometer.com/?maproute=1002731 from where a corresponding GPX file can also be downloaded.
The route can also be viewed on Google Maps at https://www.google.com/maps/d/u/0/edit?mid=1Wku76uHovXi7CDAEgrtpqKLDmKZKrBg&ll=51.70861529201181%2C-0.35668000000000255&z=13.

Leader Dick B