West Iceland is linked to Southwest and North Iceland via the ring road. Note that if arriving from Reykjavík, you will most likely go through a tunnel under Hvalfjörður the fjord marking the start of West Iceland. This is the only toll road in Iceland, and for vehicles shorter than 6 meters each trip costs 1000 kr. If you'll be going back and forth a lot, there's a discount card for ten trips at 6350 kr. Whichever direction you're driving, the toll booths are on the north. An alternative to paying is to drive around Hvalfjörður. It's a scenic drive, and well worth it if you have the time. Since the tunnel was built, the traffic levels are very low and sights include the country's only whaling station in operation as well as innumerable waterfalls, mountains and rivers. However it's a long drive, 59km as opposed to the 6km long tunnel.
If you're arriving from the Westfjords, there are two roads, one on each coast of the peninsula that links the regions. Alternatively you can take a ferry from Brjánslækur, on the south coast of the Westfjords, called Baldur (http://seatours.is/FerryB...). Note that Brjánslækur is only a ferry port and the closest towns are Bíldudalur and Patreksfjörður, both around 50km away. The terminal on the West Iceland side of the route is Stykkishólmur on Snæfellsnes, with a stop in Flatey on the way.
There are no scheduled flights into West Iceland.