This might be the most obscure signed state highway in the Hartford area. It doesn't intersect the Berlin Turnpike (though it gets close); and the other major highway it intersects (Route 9) doesn't mention it by number.
Commissioned in 1932, and has had few or no routing changes since then.
However, Route 174 was almost deleted from the state highway system in the state's Route Reclassification in 1962. The state wanted to turn it over to the towns, possibly because it paralleled Route 175, another state highway.
The city of New Britain insisted the state retain control, because of the road's "increasing importance in arterial traffic flow of the city." The state countered that Route 174 is a "short leg", and the traffic load was not as heavy as the city contended.
Route 174 even disappeared from a few state maps in the 1960s, which must have pleased city officials. However, it remains in the state highway system to this day, along with several other short leg routes in the area.