Transportation in Connecticut is predominantly via highway. Bradley International Airport (BDL) is located in the central part of the state (15 miles (24 km) north of Hartford). Another large airport, mostly used by corporate executives and those who own private aircraft, is the Oxford Airport in western Connecticut. The airport is located 15 miles (24 km) east of Danbury and 12 miles (19 km) southwest of Waterbury. There is railway service along the coastline from New York City to Boston, including commuter rail service between New Haven and New York and a new commuter service along the river north of New Haven, with spur service running northwards to cities such as Hartford. Bus service is supplied by Connecticut Transit, owned by the Connecticut Department of Transportation. In practice, most Connecticut residents find public transportation not fully adequate for all their needs and either own a private vehicle or have access to one.

The glaciers carved valleys in Connecticut running north to south; as a result, many more roadways in the state run north to south than do east to west, mimicking the previous use of the many north-south rivers as transportation. The Interstate highways in the state are I-95 (the Connecticut Turnpike) running southwest to northeast along the coast, I-84 running southwest to northeast in the center of the state, I-91 running north to south in the center of the state, and I-395 running north to south near the eastern border of the state. The other major interstate traffic arteries in Connecticut are the Merritt Parkway and Wilbur Cross Parkway, which together form Connecticut State Route 15, running from the Hutchinson River Parkway in New York State parallel to I-95 before turning north of New Haven and running parallel to I-91, finally becoming a surface road in Berlin, Connecticut. This road and I-95 were originally toll roads; they relied on a system of toll plazas at which all traffic would stop and pay an incremental fare, rather than the alternative system of providing drivers a ticket where they entered the highway and charging them when they exited. A series of terrible crashes at these plazas eventually led to abandonment of the whole toll system in 1988. Other major arteries in the state include State Routes 8 and 25 and U.S. Highway 7.

I-95 from south of New Haven to the New York border is one of the most congested highways in the United States due to increasing population density, increasing business in the New York area, and a general increase in American driving, and the congestion spills over to clog the parallel Merritt Parkway. At rush hours, multiple backups tens of miles long are common, and the daily radio broadcasts of where crashes have completely blocked traffic are a fact of life for commuters in this area. As a result, commuter rail is also heavily crowded, along with parking facilities and traffic at the stations. Funds to relieve the situation, either by enhancing commuter rail, increasing highway capacity, or both, are lacking, and the problem is noted as one hindering further economic development for the state.

Homes in western Connecticut are quite expensive, often starting around $500,000. In this region of the state, a three-bedroom home on 1/4 acre (1000 m2) might easily run about US$1 million. Although Connecticut has the highest percentage of million-dollar homes in the Northeast (and third in the country), the majority of these homes are located in the western third of the state and in the Hartford suburbs.

The highest peak in Connecticut is Bear Mountain in Salisbury in the northwest corner of the state. Once the location of a stone tower, currently a stone plaque alongside the Appalachian Trail identifies the point as "the highest ground in Connecticut, 2,354 feet above the sea"; however, this is wrong on both counts. The current estimate of the height of the summit is only 2,316 feet 706 m); and although it is the highest peak in Connecticut, it is not actually the highest point in the state. That distinction belongs to an anonymous location just east of the point where Connecticut, Massachusetts, and New York meet (42° 3' N; 73° 29' W), on the southern slope of 2,453 foot (747 m) high Mount Frissell, whose peak lies 740 feet (225 m) north in Massachusetts. Only a green metal stake set into a rock ledge marks this, the 2,372 foot (723 m) high top of Connecticut. Connecticut is the only state whose highest point is not also its highest peak.