# Route 159 (Connecticut–Massachusetts)

Route 159 is a 21.14-mile-long (34.02 km) state highway connecting the Hartford and Springfield areas in the U.S. states of Connecticut and Massachusetts. It begins at the Hartford–Windsor town line and proceeds northward along the west bank of the Connecticut River towards Agawam, Massachusetts. The route ends at the junction of Route 147 and Route 75 in Agawam center just south of the West Springfield city line. The route was originally designated as U.S. Route 5A in 1932 and was renumbered to its modern designation in October 1968.

## Route description

Route 159 begins at the Hartford–Windsor town line as a continuation of Main Street. It heads north as Windsor Avenue before meeting I-91 at Exit 41. In Windsor, it underpasses I-291, with access to and from the east provided by Deerfield Road. Almost immediately, it meets the eastern end of Route 218. After passing the east end of Route 178, Route 159 enters the center of Windsor, passing the town green before intersecting the southern end of Route 75. It then crosses the Farmington River, and starts to parallel the west bank of the Connecticut River, which it will for most of the rest of its length. In Windsor Locks, it meets I-91 once again at Exit 49, and has a brief overlap with Route 140. It passes along the eastern side of Suffield, where it has a brief overlap with Route 190. It then crosses the Massachusetts state line into Agawam, where it passes by Six Flags New England before entering the center of town. North of the center, Route 159 has an interchange with Route 57, before continuing north along Main Street to the intersection of Route 75 and Route 147 just south of the Westfield River and the West Springfield city line.
Route 159 in Windsor is also known as the Kasmir Pulaski Memorial Highway.

## History

Modern Route 159 roughly follows the path of the Upper Boston Post Road between Hartford and Springfield. In the 1920s, current Route 159 in Connecticut, with a few minor exceptions, was a primary state road designated as State Highway 110. Around 1930, the continuation in Massachusetts was numbered as State Route 5A, which ran along Main Street but continued north along River Road to the South End Bridge, where it crossed into Springfield to connect with US 5. In the 1932 state highway renumbering, the route in both Connecticut and Massachusetts was designated as US 5A. However, by 1938, Massachusetts redesignated its portion of the route as State Route 5A, truncating US 5A to the state line. The new State Route 5A was also relocated to follow Main Street into West Springfield, then continuing along River Street, Park Street, and Elm Street, where it ended at US 5. In October 1968, Connecticut decommissioned its US 5A and the road was redesignated in both states as Route 159. The portion in West Springfield, which was not state-maintained, became an unnumbered road.

## Major intersections

Mileposts reset at the state line.
| State | County | Location | mi | km | Destinations | Notes |
| Connecticut | Hartford | Hartford–Windsor line | 0.00 | 0.00 | Main Street – North Hartford | Continuation south |
| Connecticut | Hartford | Windsor | 0.23 | 0.37 | I-91 – Hartford, Springfield | Exit 41 on I-91 |
| Connecticut | Hartford | Windsor | 1.20– 1.24 | 1.93– 2.00 | I-291 east / Route 218 west – South Windsor, Manchester, Bloomfield, West Hartford | Eastern terminus of Route 218; exit 1D on I-291 |
| Connecticut | Hartford | Windsor | 2.66 | 4.28 | Route 178 west (Park Avenue) – Bloomfield | Eastern terminus of Route 178 |
| Connecticut | Hartford | Windsor | 3.76 | 6.05 | Route 75 north / Route 305 west – Windsor Locks, Suffield, Bloomfield | Southern terminus of Route 75; eastern terminus of Route 305 |
| Connecticut | Hartford | Windsor Locks | 8.52 | 13.71 | I-91 – Hartford, Springfield | Exit 49 on I-91 |
| Connecticut | Hartford | Windsor Locks | 9.12 | 14.68 | Route 140 west (Elm Street) – Bradley International Airport | Southern end of Route 140 concurrency |
| Connecticut | Hartford | Windsor Locks | 9.42 | 15.16 | Route 140 east (Bridge Street) – East Windsor, Ellington | Northern end of Route 140 concurrency |
| Connecticut | Hartford | Suffield | 13.82 | 22.24 | Route 190 east (Hazard Avenue) – Enfield | Southern end of Route 190 concurrency |
| Connecticut | Hartford | Suffield | 14.43 | 23.22 | Route 190 west (Thompsonville Road) – Suffield Center | Northern end of Route 190 concurrency |
| Connecticut–Massachusetts state line | Connecticut–Massachusetts state line | Connecticut–Massachusetts state line | 16.820.00 | 27.070.00 | Route transition | Route transition |
| Massachusetts | Hampden | Agawam | 3.08 | 4.96 | Route 57 east – Springfield | Interchange |
| Massachusetts | Hampden | Agawam | 4.32 | 6.95 | Route 75 south / Route 147 – Suffield, CT, West Springfield, Feeding Hills | Northern terminus; northern terminus of Route 75 |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus Route transition |||||||