Hitchin Flyover Walk - Date confirmed - Now fully booked

I have learned that the Flyover walk has now been confirmed for the 11th May.  The walk will be 3.7 miles in total.  Booking is essential and the cost will be £5 which all goes to local charity.  Groups will set off every half hour from 11.00am to 3.00pm.
27th April - I have now learned that all the walk start times have been fully booked

Here is a copy of the poster advertising the opportunity.

And the joining instructions and rules.