The ancient capital of Sodor is the 'city' of Suddery but Tidmouth has grown to be the largest town on the island. The summit is reached by the Culdee Fell Railway, which is based on the Snowdon Mountain Railway in Wales. Its highest mountain is Culdee Fell, which was modelled on Snowdon: the ridge of Devil's Back copies the Clogwyn ridge on Snowdon. It has various small industrial sites, including a prosperous stone quarry served by the island's railway. The island's language is Sudric, though like Manx, this is falling out of use. The place names on Sodor are mostly a mixture of Manx and Norse. Its northeast edge overrides and replaces the real Walney Island. Its northwest coast is separated from the Isle of Man by a sea strait called the Sudrian Sea, four miles wide. It is often shown as roughly diamond-shaped, 62 miles wide east to west and 51 miles long north to south. The smaller truck is based on Sodor Island 3D's 5-plank wagons (made for Trainz), except with the S2-style face.Sodor is usually shown as much larger than Man. The tank wagon is based on the ones seen in Season 4's 'Toad Stands By'. The Trucks here are given full faces as per Season 2, whereas in Season 1, they had pasted-on eyes and a mouth for faces (and even then, only one face - a cross face - was made). But some of the most noteworthy ones are the time when Thomas first pulled them only to be pushed down Gordon's Hill, them pushing James down the same hill, causing him to cash into some tar tankers, them pushing Duck into a shed in which a barber had set up shop, and when some ballast trucks pushed Oliver into a turntable well.

There are various stories of the Troublesome Trucks. While trucks are generally badly behaved, it's said that ballast trucks are the worst of all. Usually, this is done by either holding their engine back when going uphill, or pushing an engine too fast when going downhill. They love to take advantage of gravity whenever they carry heavy loads. The Troublesome Trucks (or the Foolish Freight Cars if you prefer the American terminology) are, as their title suggests, very troublesome.

Sodor workshops rolling stock