Wikipedia:WikiProject U.S. Roads/Connecticut/List of defunct route numbers

List of route numbers designated after 1932 that are not currently in use:

Route 8A: now Route 110 between US 1 and Route 113
Route 9A: now Route 154 and Main St from Middletown to Old Saybrook, and also an earlier one in Old Saybrook became part of Route 80 (now Essex Rd).
Route 10A: now SR 707; one in Cheshire now Main St and Maple St; another in Plainville from Route 10 to East Main St and overlapping with what is now route 372 is now Whiting St
Route 15A: now Route 17A; one in Union now Route 171 and Route 190
Route 16A: now Main Street (East Hampton)
Route 17 (first use): now SR 602; reused to renumber part of Route 15 after it was rerouted onto the freeways
Route 17A (other use): now Main Street (Glastonbury)
Route 18: became SR 525; now Route 372 between Route 3 and Route 99
Route 29: now Route 124 to match New York
Route 32A: now Williams St and Old Norwich Road (Waterford)
Route 35A: now SR 835
Route 37A: now Route 39 and Warwick Road; old Route 39 is now Milltown Road (New Fairfield)
Route 49 (first use): now route 272 (became part of route 72 first); reused to renumber Route 95 because of I-95
Route 51: now US 1 north of I-95 in Old Lyme and East Lyme
Route 52: now I-395
Route 58A: now Coal Pit Hill Road (Danbury)
Route 65: now Noble Avenue (Bridgeport), Huntington Turnpike, Route 8 (built over this road), SR 714
Route 65A: now SR 711, Shelton Road (was part of Route 113 (Trumbull))
Route 67A: now SR 867
Route 76: now North Street (Windsor Locks)
Route 78 (first use): now part of Route 140 and old Route 140 is now Spring Street (Windsor Locks); reused to match Rhode Island
Route 84: became route 95, now Route 184
Route 86: now Route 156 north of US 1
Route 91: now Route 198 between US 6 and Route 171, and Route 171 between Route 198 and US 44
Route 93: now Route 169
Route 95: now Route 49; used to renumber Route 84, but renumbered to Route 184
Route 100 (first use): became Route 39 and Route 37A from Route 37 to Danbury; this section of Route 37A is now part of Route 39
Route 101 (first use): now US 44 from US 7 to Rhode Island; reused to renumber Route 202 because of US 202
Route 103 (first use): now Route 53 from Newtown Turnpike to Norwalk Town Line (Wilton); reused on upgrade of SR 720 and SR 750
Route 105: now Lyons Plain Road (Weston)
Route 106 (first use): now Center Road (Easton); reused on a new route
Route 110A: now Route 110 between US 1 and Route 113
Route 113A: now Route 113 around Sikorsky Airport
Route 116 (first use): now route 118; reused to match New York
Route 117 (first use): became route 72; now route 72 and route 4 from near Plymouth to Torrington; reused for a new route and part of old Route 27
Route 118 (first use): now West Avenue (Darien); reused to renumber Route 116
Route 119 (first use): now part of Route 69 from Waterbury to Bristol
Route 119: now part of Route 201 and SR 627 from SR 184 to SR 2 (North Stonington)
Route 124 (first use): now SR 833 and SR 834 (Clayton Road); reused to match New York
Route 129: now Railroad Street, Wellsville Avenue, Merryall Road, and Squire Hill Road (New Milford)
Route 130 (first use): now New Preston Hill Road, Cherniske Road, West Meltinghouse Road, and Bulls Bridge Road from Route 45 to New York; reused on upgrade of SR 771 and SR 769
Route 131 (first use): became Route 199, one portion removed from the state highway system later; reused on upgrade of SR 874
Route 134: became SR 857, now Route 109 from US 202 to Route 47, old Route 109 became Route 209
Route 135 (first use): now Old Watertown Road, Tranquility Road, and Route 188 from US 6 to Route 63; reused for new road in Fairfield
Route 138A: now Church Street (Voluntown)
Route 139A: now School Ground Road (Branford)
Route 140A: now Route 140 in Ellington Center
Route 141: now Route 22 between Route 80 and US 1
Route 143: now Route 146 between South Main Street and 2nd Ave; old Route 146 along Leetes Island Road was removed from the system
Route 144: now Bushy Hill Road (Deep River), Main Street (Essex)
Route 148A: now Main Street (Chester)
Route 154A: now Maple Avenue (Old Saybrook)
Route 156A: now Lyme Street and McCurdy Road between Route 156 and US 1
Route 158: now Campbell Ave and Route 122 from Main Street to Route 243
Route 159 (first use): now Cherry Hill Road (Middlefield); reused to replace US 5A
Route 168 (first use): now Route 22 between US 5 and Route 17; reused to match New York
Route 169 (first use): now route 27 (portion north of Route 184 became part of Route 117); reused to renumber Route 93
Route 171 (first use): now Waterhole Road and Trowbridge Road from Route 16 to Route 149; reused to renumber Route 91
Route 176A: now Main Street (Newington) and South Street (West Hartford)
Route 180: Durham to Haddam; not built
Route 181A: now Morgan Brook Road (Barkhamsted)
Route 184 (first use): became Route 187, Park Ave, and Route 178 (Bloomfield) from US 44 to Route 185 (one section on the west has since been bypassed); reused to renumber Route 95 (originally Route 84)
Route 190A: now North Main Street (Enfield)
Route 199 (first use): now US 44 from US 7 to New York
Route 201 (first use): now Route 97 from US 44 to US 44 (Pomfret)
Route 202: now Route 101
Route 211: now Route 14A from Route 14 to Route 49 (then Route 95)
Route 291: placeholder for IH-291; became IH-291 when it was completed

U.S. Route 5A
U.S. Route 6A
U.S. Route 44A
U.S. Route 202A

Interstate 82 (later part of unbuit IH-84 from Hartford to Providence; some is signed as IH-384 and US 6; rest not built)
Interstate 86 (signed as IH-84; IH-84 is signed as IH-384 east of there and is/was proposed to go east to Providence; may not necessarily be cancelled)
Interstate 87 (Signed east concurrent with IH-84 and on current IH-684; became IH-684 as designation moved westward; Route 87 was to be renumbered to Route 287, but I-87 was moved out of the state, so Route 87 kept is number)
Interstate 290 (original proposed number to replace Route 52; ended up being IH-395 instead)
Interstate 284 (unbuilt from IH-84/Route 2 interchange to IH-291 in South Windsor; the northwest leg of IH-291 was cancelled and nevel built; the southwest leg of IH-291 is now part of Route 9)
Interstate 484 (unbuilt from IH-84 to IH-91 in Hartford)
Interstate 491 (unbuilt from IH-91 northeast to IH-84 in Hartford; later became IH-86 and this section was later cancelled; now partly Route 3)