- A303 between A30 and B3170, Devon (Grid ref ST221080)
- A303 between B3170 and Devon boundary, Devon (Grid ref ST247103)
- A303 between Somerset boundary and A358, Somerset (Grid ref ST300136)
- A303 between A358 and A356, Somerset (Grid ref ST450167)
- A303 between A356 and A3088, Somerset (Grid ref ST479188)
- A303 between A3088 and spur to A37, Somerset (Grid ref ST492200)
- A303 between A303 main route mid-junction and A37, Somerset (Grid ref ST515225)
- A303 between spur to A37 and A372, Somerset (Grid ref ST520239)
- A303 between A37 and B3151, Somerset (Grid ref ST538251)
- A303 between B3151 and A359, Somerset (Grid ref ST570250)
- A303 between A359 and A359, Somerset (Grid ref ST600261)
- A303 between A359 and A371, Somerset (Grid ref ST653266)
- A303 between B3081 and A303 main route, Somerset (Grid ref ST707279)
- A303 between A371 and B3081, Somerset (Grid ref ST740296)
- A303 between B3081 and Somerset boundary, Somerset (Grid ref ST754299)
- A303 between Dorset boundary and Dorset boundary, Dorset (Grid ref ST770299)
- A303 between Wiltshire boundary and A350, Wiltshire (Grid ref ST805328)
- A303 between A350 and A303 main route, Wiltshire (Grid ref ST885341)
- A303 between A350 and A303 spur, Wiltshire (Grid ref SU000375)
- A303 between A303 main route and A36, Wiltshire (Grid ref SU011380)
- A303 between A303 spur and A360, Wiltshire (Grid ref SU066407)
- A303 between A360 and A344, Wiltshire (Grid ref SU102414)
- A303 between A360 and A344, Wiltshire (Grid ref SU126420)
- A303 between A344 and A345, Wiltshire (Grid ref SU150420)
- A303 between A345 and A3028, Wiltshire (Grid ref SU160422)
- A303 between A3028 and A338, Wiltshire (Grid ref SU209428)
- A303 between A338 and A342/A343 roundabout, Hampshire (Grid ref SU250441)
- A303 between A342/A343 roundabout and A303 spur to A343, Hampshire (Grid ref SU341453)
- A303 between A343 and A303 main route, Hampshire (Grid ref SU344447)
- A303 between A303 spur to A343 and A3057, Hampshire (Grid ref SU350445)
- A303 between A3057 and A3093, Hampshire (Grid ref SU380446)
- A303 between A3093 and A30, Hampshire (Grid ref SU400443)
- A303 between A303 and A30 spur, Hampshire (Grid ref SU461420)
- A303 between A303 main route and A34, Hampshire (Grid ref SU462419)
- A303 between A30 and A30, Hampshire (Grid ref SU462419)
- A303 between A30 and A303, Hampshire (Grid ref SU465419)
- A303 between A30 and A30/M3, Hampshire (Grid ref SU550446)