County routes in Suffolk County, New York, are maintained by the Suffolk County Department of Public Works and signed with the Manual on Uniform Traffic Control Devices-standard yellow-on-blue pentagon route marker. The designations do not follow any fixed pattern. Routes 26 to 50 (including former suffixed routes of CR 50) are listed below.

County Route 26

County Route 26 was the designation for New Suffolk Road from Mattituck to New Suffolk, and New Suffolk Lane from New Suffolk to Cutchogue. This designation was proposed to be relocated to the formerly proposed North Brookhaven Expressway, a former eastern extension of NY 347 from Mount Sinai to Wading River.

Major intersections

County Route 27

County Route 27 was the original designation for Middle Road on the North Fork of Long Island. This road is now known as CR 48.

County Route 27A

County Route 27A was a newer section of Middle Road in Mattituck called New Middle Road. It was merged into CR 27 before that route was replaced by CR 48.

County Route 27B

County Route 27B was Wickham Avenue, a former segment of Middle Road that is now owned by the town of Southold.

County Route 28

County Route 28 is a north-south road in southwestern Suffolk County known as New Highway and Republic Road. Officially designated as the Corporal Tony Casamento Highway, the road is a four-lane undivided highway between NY 27 and the interchange with Southern State Parkway where the road narrows down to two lanes. According to the New York State Department of Transportation, CR 28 is split into two sections: the signed portion that is New Highway between NY 27 and the Southern State Parkway, and the unsigned Republic Road between the Town of Babylon/Town of Huntington town line and CR 5 (Ruland Road).

Route description The road begins at NY 27 just west of the intersection of CR 2 (Straight Path), and an Educational Bus Transport garage for school buses and intercity buses of Suffolk County Transit. This section of the road then curves towards the old section which runs along Trinity Cemetery, the site of the former Zahn's Airport, and behind the Sisters of St. Dominic Motherhouse Complex, which was previously known as the Queen of the Rosary Academy. After bi-secting Albany Avenue, the road approaches an at-grade crossing of the Central Branch of the Long Island Rail Road and immediately intersects NY 109. After the immediate intersection with NY 109, CR 28's southern section terminates with the Southern State Parkway, but the roadway continues northward on the south and eastern circumferences of Republic Airport.

North of the industrial zone in East Farmingdale, Republic Road regains the designation of CR 28 at the Babylon/Huntington town line. Republic Road and CR 28 terminates 0.41 miles north of the line at CR 5 (Ruland Road) in Melville; however, just to the east of this terminus is a de facto extension called Maxess Road, which leads to the eastbound service road of the Long Island Expressway between NY 110 and CR 3 (Pinelawn Road). This extension, however, is not included on CR 28's route.

Major intersections

County Route 29

County Route 29 was an unsigned county route connecting CR 93 to the Long Island Expressway. The road was widened during the period that the Ronkonkoma Station was facing major reconstruction itself, and included a replacement for the wooden bridge that previously crossed over the Main Line of the Long Island Rail Road. The CR 29 signs were installed between 1989 and 1995, but have since been taken down.

Within the town of Islip, the road is named Smithtown Avenue. After it crosses the Main Line of the Long Island Rail Road and simultaneously the Town of Islip–Town of Brookhaven town line, it becomes Ronkonkoma Avenue, a name that continues north of the terminus of I-495 until it reaches Hawkins Avenue in Lake Ronkonkoma. The route is no longer recognized by the Suffolk County Department of Public Works nor the New York State Department of Transportation.

Major intersections

County Route 30

County Route 30 was the north-south road along the east side of Lake Montauk, known as East Lake Drive. The east side of this road consists of parts of Montauk County Park, a residential enclave, and Montauk Airport. The road terminates at the a parking lot north of the Inlet Seafood Restaurant on the Block Island Sound.

Major intersections The entire route is located in Montauk.

County Route 31

County Route 31 is a short north-south county highway running across rural eastern Suffolk County. The road serves as a connection between Westhampton Beach and the Riverhead area, feeding directly into CR 104 as it makes its way north.

Route description The road begins at Montauk Highway (CR 80), just north of the downtown area of Westhampton Beach. It serves in function as a continuation of Oak Street, which heads south to connect with the town's main street before crossing over to the Dune Road beaches.

Heading north, this arrow-straight portion of the road crosses the Long Island Rail Road's Montauk Branch railroad tracks and then runs through the grounds of Francis S. Gabreski Airport, a former base of the United States Air Force, which is now home to the 106th Rescue Wing of the New York Air National Guard.

North of the base, the road continues through a section of the Long Island Central Pine Barrens, which feature the indigenous dwarf pine. This area fell victim to a widespread wildfire that burned a significant portion of the core of the Pine Barrens in 1995. The section of CR 31 within the village of Westhampton Beach is ceremoniously dedicated "Volunteers Way" in honor of volunteer first responders to the Sunrise Fire.

The road widens as it crosses NY 27, with which it has a full cloverleaf interchange. About one-half mile beyond this interchange, the road ends at a traffic circle with CR 104.

History Between January 18, 1961 and May 23, 1972, CR 31 was extended south of Montauk Highway between Oak Street and Mill Road (formerly CR 100). Mill Road was intended to be converted into part of the formerly proposed Port Jefferson–Westhampton Beach Highway.

Major intersections

County Route 32

County Route 32 is the Ponquogue Bridge, the main two-lane highway between Ponquogue Point on Westhampton Beach Barrier Island and the mainland, which, through a maze of roadways, connects to downtown Hampton Bays. The route used to be designated north of the bridge along Lighthouse Road, Foster Avenue, Shinnecock Road, and Ponquogue Avenue to Montauk Highway in Hampton Bays, but neither the Suffolk County Department of Public Works or the New York State Department of Transportation recognize that portion of the roadway as CR 32, just the Ponquogue Bridge portion. The formerly proposed Ponquogue Causeway was intended to either run parallel to or replace CR 32 between the 1930s and 1960s, but the roadway never came to fruition.

Major intersections The entire route is in Hampton Bays, New York.

County Route 32A

County Route 32A was concurrent with CR 32 from Montauk Highway to the LIRR station.

County Route 32B

County Route 32B was Foster Avenue and the former Ponquogue Bridge. It was integrated with CR 32.

County Route 33

County Route 33 was the designation for Cranberry Hole Road, Promised Land Road, and Napeague Meadow Road. The entire road is a former routing of Montauk Highway.

CR 33 began in Amagansett at the intersection of NY 27 and Bluff Road as Cranberry Hole Road, and carried over the Cranberry Hole Road Bridge above the Montauk Branch of the Long Island Rail Road, the easternmost LIRR bridge to exist. The name Cranberry Hole Road continues until the intersection with Bendigo Road (former CR 33A and CR 74). From there it the road becomes Promised Land Road. Both segments of CR 33 ran along the northern edge of Napeague State Park, and continued to run through the park even as it turns southeast onto Napeague Meadow Road. Promised Land Road continues northeast as Lazy Point Road where it enters "downtown" Napeague.

The former route crosses the LIRR Montauk branch for the second time, but this time it is at an at-grade crossing, where it enters a section of Napeague formerly known as East Hampton Beach, before finally terminating at Montauk Point State Parkway (NY 27).

Major intersections

County Route 33A

County Route 33A was for Abrahams Landing Road and Bendigo Road. It was a former suffixed route of CR 33, that is now unmarked CR 74.

County Route 34

County Route 34 is Deer Park Avenue between the Village of Babylon/Town of Babylon line and New York State Route 231 in North Babylon. It was a former segment of CR 35 that was established in 1970 when the New York State Department of Transportation created (what was intended to be) a temporary alignment of NY 231.

The Village of Babylon used to maintain the section of CR 34 within the village. However, the New York State Department of Transportation, as well as the Suffolk County Department of Public Works, deems that CR 34 exists outside of the Babylon village limits. Outside of the village limits, CR 34 crosses over New York State Route 27 (Sunrise Highway) as part of Exit 40, which is primarily for NY 231 to the east. Though CR 34 terminates at NY 231 in Deer Park, just south of the Southern State Parkway's exit 39, Deer Park Avenue continues northward as NY 231 well into Dix Hills.

Before its current designation, CR 34 was assigned to Greenlawn Road, today a portion of CR 9 along with Cuba Hill Road, until the late 1960s.

Major intersections The entire route is located in North Babylon.

County Route 35

County Route 35 serves as a de facto extension of NY 231, spanning from the northern terminus of NY 231 and the Northern State Parkway in Dix Hills northwest to NY 110 in the hamlet of Huntington. The road originally included NY 231 and CR 34 until 1970, when the New York State Department of Transportation turned the segment between Southern and Northern State Parkways into the temporary alignment of NY 231, before the hopeful transfer of the road onto the formerly proposed Babylon–Northport Expressway. The south end of CR 35 and CR 66 and the north end of NY 231 was intended to include a formerly proposed North Deer Park Avenue Spur leading to the unbuilt expressway.

Route description The segment of CR 35 between NY 231 and NY 25 is four-lanes wide and is known as Deer Park Road West, as opposed to CR 66, which is known as Deer Park Road East. CR 35 is the last intersection with Old Country Road before both move north and intersect with NY 25. After this intersection, CR 35 narrows down to two lanes and becomes Park Avenue, which turns to the northwest at the 2nd Precinct of the Suffolk County Police Department before intersecting with CR 86 in west Elwood. At the north end of Dix Hills Road, the road narrows down to two lanes and contains frontage roads for residences. From there, the road serves as the east end of Maplewood Road, where it briefly overlaps with New York State Bicycle Route 25A until it reaches the west end of Little Plains Road, a block away from Little Plains Park.