Salisbury had a grid pattern back in the 13th century. But mostly small roads follow old field boundaries that can be very old and bendy. Even new developments will fit into old field layouts and have curved roads.
>* But mostly small roads follow old field boundaries that can be very old and bendy.* //
The places I know of - Lincolnshire and East Lothian - where roads follow field boundaries have a lot of straight roads with 90deg bends. Interesting you suggest that field boundary following would make roads more "bendy" (suggesting non-straight edges and non right-angles).
Perhaps the fields of Salisbury weren't dissected for inheritance purposes or are older and follow more natural lines?
It depends how old the field is. Around villages you can see very irregular fields that are very old. But a lot of the larger fields have straighter boundaries as a result of intentional enclosure. In lowlying parts a lot of the land is drained, and smaller drainage channels will follow straight lines.
