| Province | NB |
|---|---|
| Route | 3 |
| Length | 95 km |
| Maint | New Brunswick Department of Transportation |
| Length round | 1 |
| Established | 1927 |
| Direction a | South |
| Direction b | North |
| Terminus a | near St. Stephen |
| Junction | near McAdam |
| Terminus b | near Longs Creek |
| Previous route | 2 |
| Next route | 4 |
Route 3 is 92 kilometres long and goes from Route 170 in St. Stephen to Route 2 (the Trans-Canada Highway) at Longs Creek, near Fredericton.
From St. Stephen, Route 3 goes north along the west bank of Dennis Stream, through the community of Moores Mills. The road turns northeast through Lawrence Station and mostly uninhabited land to meet Route 4 near York Mills. From there, Route 3 continues in a northeasterly direction through Harvey Station, then turns north to the Trans-Canada Highway at Longs Creek.
There have been no major changes or realignments to Route 3 since the 1950s.