What a brilliant horse!
This bridleway bridge is almost certainly non-compliant as the standards for the sides of bridges has been raised and so has the infilled sections. The current height for parapets is found in the Horse Crossing Leaflet Number 13 on the British Horse Society Leaflet. Bridleway Bridges Ref 1982. 1.8 metres high with an 18" solid infillbut.
Contact the Highways Agency and ask them for the bridge to be upgraded to current specifications. Your local BHS bridleway officer would be pleased to assist you.
Awwww.....likkle Po....I'm going to miss the ginger sausage....your not a bad old stick either Pedantic!!!!