I would probably say "Where the street ends, turn left ... ", but see:

Proceed on 295 East to a "T" intersection (approximately 10 miles). At "T" intersection, turn left onto Route 41 North.

Ist eine T-Kreuzung nicht eigentlich eine Einmündung?

An der nächsten T-Kreuzung gehen Sie nach links in die Heßbrühlstraße

Turn left into Hessbrühlstrasse at the next T-junction.

I agree with nina_glndwr. At the t-junction you turn left...

I'd say T-junction too. It's the normal term in British English, but, judging from Robert's post, I wonder whether it would be understood by Americans. The translation might depend on PaulE's audience.

t-junction works fine here in the US

Sorry, Solo, I had to go.
T-Junction is seems perfect to me!
Thanks a lot.