The Ranty Highwayman)
Suburban places are often crossed by railways, large roads and rivers which means crossing opportunities are limited and so they funnel all transport modes together. Sometimes we get footbridges which are often a remnant of an historic right of way or public footpath. They can be secluded and lonely. This one just had steps, so it’s not accessible to all.
There are countless railway bridges dating from the 1950s (and before). Their construction often means that the footways cannot take any heavy loads and so the risk of a lorry being driven onto the footway presents a real risk of damage or partial collapse (called Accidental Wheel Loading); plus with brick parapets (the walls), they cannot take an impact from a heavy vehicle.
Rail crashes such as Great Heck and Oxshott showed the impacts of vehicles being driven (or crashed) onto railway lines. The type of temporary barrier show here (MASS) are designed to stop people driving onto the footway and for lorries, the shape redirects the line of travel back onto the road.