In 1932, the Highway Department of the U.S. state ofConnecticut (now known as theConnecticut Department of Transportation) decided to completely renumber all itsstate highways. The only exceptions were theU.S. Highways and some of the New England Interstate Routes. Between 1922 and 1932, Connecticut used astate highway numbering system shared with the otherNew England states. Major inter-state trunk routes used numbers in the 1-99 range, primary intrastate highways used numbers in the 100-299 range, and secondary state highways used numbers in the 300+ range.
In 1926, at the behest of theAmerican Association of State Highway Officials, four of the nine New England Interstate Routes that passed through Connecticut becameU.S. Routes. At this time, the adjacent states ofMassachusetts andRhode Island abandoned the New England highway numbering system but Connecticut still used it for several more years. This led to a situation where U.S. Routes were co-signed with New England Routes (in particular U.S. Route 5/New England Route 2 and U.S. Route 6/New England Route 3).
In 1932, the Highway Department decided to abandon the New England numbering system as well by completely reorganizing the state highway system. The renumbering completely altered the previously existing state highway numbers. In addition, not only were the highways renumbered, some old state highways were combined, some were split, some were deleted, and some new ones were also created.
The table below lists the highways that were created in the 1932 renumbering, indicating which old state highways they were created from, and their current status:
 |
| 1932 Route | Pre-1932 State Highway number(s) | Current designation | Notes |
|---|---|---|---|
| 2 | NE-17 east ofHartford | Route 2 | Hartford to Norwich upgraded to expressway. Portions of old surface alignment are now unsigned state roads. |
| 4 | SH 123 (Cornwall-Canton), SH 138 (Canton-Farmington) | Route 4 | |
| 8 | NE-8 | Route 110,Route 8 | Upgraded to expressway with a different alignment south ofShelton. Portions of old surface alignment are now unsigned state roads. |
| 9 | NE-10 south ofGranby | Route 154,Route 99,Route 189 | Upgraded to expressway with a different alignment north ofMiddletown (seeRoute 9). |
| 10 | SH 118 (New Haven-Milldale),NE-3 (Milldale-Farmington), SH 116 (Farmington-Granby),NE-10 north of Granby | Route 10 | |
| 12 | NE-32 (Groton-Norwich),NE-12 north of Norwich | Route 12 | |
| 14 | NE-3 (Woodbury-Milldale), SH 111 (Milldale-Willimantic), SH 141 (Willimantic-Plainfield), SH 103 (Plainfield-RI) | Route 64,Route 322,Route 66,Route 14 | West of Willimantic was renumbered to US 6A in 1941. |
| 15 | SH 114 (New Haven-Durham), SH 112 (Durham-Middletown), SH 104 (Portland-Glastonbury), NE-17 (Glastonbury-East Hartford), SH 313 (East Hartford-Talcotville), SH 107 (Talcotville-Rockville), SH 166 (Rockville-Stafford Springs), SH 105 (Stafford Springs-MA) | Route 17,Route 30,Route 190 | |
| 19 | Original alignment ofNE-32 inStafford | Route 19 | |
| 20 | SH 133 (Winsted-Granby), SH 343 (East Granby-Windsor Locks), SH 105 (Enfield-Stafford Springs) | Route 20,Route 190 | |
| 25 | SH 122 (Bridgeport-Newtown), SH 156 (Newtown-Brookfield), SH 182 (Brookfield-Bridgewater), SH 125 (Bridgewater-New Milford), SH 128 (New Milford-Torrington) | Main Street,Route 25,Route 133,Route 67,U.S. Route 202 | Upgraded to expressway between Bridgeport and Trumbull. |
| 29 | SH 302 (Darien-NY) | Route 124 | |
| 32 | NE-12 (New London-Norwich), NE-32 (Norwich-Stafford Springs), SH 334 (Stafford Springs-MA) | Route 32 | |
| 33 | SH 176 (Westport-Wilton), SH 304 (Wilton-Ridgefield), SH 143 (Ridgefield-NY) | Route 33,Route 116 | |
| 34 | SH 117 (New Haven-Newtown) | Route 34 | |
| 35 | NE-3 (NY line to US 7 near Ridgefield) | Route 35 | |
| 37 | SH 136 (Danbury-Sherman), SH 131 (Sherman to US 7) | Route 37 | |
| 39 | SH 194 (New Fairfield-Sherman), SH 136 (Sherman-Gaylordsville) | Route 39 | |
| 41 | NE-4 (Sharon-MA) | Route 41 | |
| 43 | SH 132 (Cornwall-South Canaan) | Route 43,Route 63 | |
| 45 | SH 152 (New Preston-Cornwall Bridge) | Route 45 | |
| 47 | SH 154 (Woodbury-New Preston) | Route 47 | |
| 49 | SH 312 (Torrington-Norfolk) | Route 272 | |
| 53 | (Georgetown-Danbury) | Route 53 | |
| 55 | (NY line to Gaylordsville) | Route 55 | |
| 57 | (Westport-Weston), SH 158 (Weston-Newtown) | Route 57, Newtown Turnpike | |
| 58 | SH 124 (Bridgeport-Danbury) | Route 58,Route 302,Route 53 | |
| 59 | SH 306 (Bridgeport-Monroe) | Route 59 | |
| 61 | SH 130 (Woodbury-Goshen) | Route 61,Route 63 | |
| 63 | SH 120 (Woodbridge-Naugatuck), SH 341 (Naugatuck to NE-3), (NE-3 to Watertown), (Watertown-Morris) | Route 63 | |
| 65 | SH 316 (Bridgeport-Shelton) | Route 8 | Original surface alignment is now an unsigned state road. |
| 67 | SH 120 (New Haven-Woodbridge), SH 147 (Woodbridge-Southbury), SH 125 (Southbury-Bridgewater) | Route 63,Route 67 | |
| 68 | SH 325 (Naugatuck-Cheshire) | Route 68 | |
| 69 | SH 348 (Bethany-Waterbury) | Route 69 | Extended by 1938 along old Route 119/SH 172 (Waterbury-Bristol). |
| 70 | SH 323 (Waterbury-Cheshire), SH 325 (Cheshire-Meriden) | East Main Street,Route 70 | |
| 71 | SH 113 (New Britain-Hartford) | Route 71,Route 173, New Britain Avenue | West Hartford-Hartford became US 6A in 1934. |
| 72 | SH 346 (Middletown-Cromwell), SH 319 (Cromwell-Berlin), SH 162 (Berlin-New Britain), SH 113 (New Britain-Plainville) | Route 3,Route 372 | |
| 73 | SH 339 (Waterbury-Watertown) | Route 73 | |
| 74 | SH 107 (Rockville-Ashford) | Route 74 | |
| 75 | SH 362 (Windsor-Suffield), SH 110 (Suffield-MA line) | Route 75 | |
| 77 | SH 112 (Durham-Guilford) | Route 77 | |
| 79 | SH 190 (Durham-Madison) | Route 79 | |
| 80 | SH 135 (New Haven-North Branford), SH 140 (North Branford-North Guilford), (North Guilford-Killingworth), SH 175 (Killingworth-Deep River) | Route 80 | |
| 81 | SH 106 (Clinton-Higganum) | Route 81 |