New Hampshire Route 78 is a 3.45 miles (5.6 km) long secondary north–south state highway

State highway

State highway, state road or state route can refer to one of three related concepts, two of them related to a state or provincial government in a country that is divided into states or provinces :#A...

 in Cheshire County

Cheshire County, New Hampshire

-Demographics:As of the census of 2000, there were 73,825 people, 28,299 households, and 18,790 families residing in the county. The population density was 104 people per square mile . There were 31,876 housing units at an average density of 45 per square mile...

 in the southern part of the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of New Hampshire

New Hampshire

New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...

. It runs from the Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

 border to Winchester

Winchester, New Hampshire

Winchester is a town in Cheshire County, New Hampshire, United States. The population was 4,341 at the 2010 census. The primary settlement in the town, where 1,733 people resided at the 2010 census, is defined by the U.S. Census Bureau as the Winchester census-designated place...

.

The southern terminus is in Winchester at the Massachusetts state line, where the road continues south as Massachusetts Route 78

Massachusetts Route 78

Route 78 is a short south–north highway in northeastern Franklin County. Massachusetts.Route 78 begins at Route 2A in Orange, just north of the Springfield Terminal railroad tracks and the Millers River. After , the route enters the town of Warwick...

 in the town of Warwick

Warwick, Massachusetts

Warwick is a town in Franklin County, Massachusetts, United States. The population was 750 at the 2000 census. It is part of the Springfield, Massachusetts Metropolitan Statistical Area.- History :...

. The northern terminus of NH 78 is in Winchester at New Hampshire Route 10

New Hampshire Route 10

New Hampshire Route 10 is a north–south state highway in the U.S. state of New Hampshire. Its southern terminus is at the Massachusetts state line in the town of Winchester. In Massachusetts the highway becomes Massachusetts Route 10. Total length of the highway is .-Route description:NH 10...

 and New Hampshire Route 119

New Hampshire Route 119

New Hampshire Route 119 is a long east–west state highway in Cheshire County in southwestern New Hampshire. The highway runs from the Massachusetts border in New Ipswich to Hinsdale on the Vermont border....

. NH 78 is named Warwick Road along its entire length.