Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 130
Situational Awareness; Human-Machine Interface
ATC Issue All Types; Inflight Event / Encounter CFTT / CFIT
Flight Crew Overrode Automation
Procedure; Human Factors; Airspace Structure
We were conducting Aircraft X at night into ABE; vectored from the north; and then given a clearance for a Visual Approach. As always; we had an approach set up; ILS 24; and while descending from the north side of the airport from 3;000 feet; the vectored altitude; to 2;400 feet; at an altitude of about 2;650 feet we received a one time (only 1) 'Terrain' warning from the TAWS (Terrain Alert Warning System); while descending very gently at about 300 feet per minute. We leveled off for a moment; there was no other terrain warning and never a 'Terrain; Pull Up' command; then as we intercepted the final; we continued to the 2;400 feet glideslope intercept altitude. There was a ridgeline north of the ILS course; which we had briefed on; but it did not show an altitude greater than 1;000 feet; so we did not think it would be a problem to start a shallow descent from 3;000 to 2;400 feet; especially at a shallow rate. This is a potential problem at night; as there are no obstacle lights on the ridge line; so I believe Approach should simply provide vectors to the ILS approach instead of just giving a 'visual.'  A little more work for ATC but a safer way of operating. Caused by ATC clearing crew to do a night visual instead of providing vectors; knowing that there are unmarked; unlit; terrain ridge lines to the north of the airport. Also caused by crew not requesting full vectors to the ILS at night. Most ATC facilities in small airports don't want to work that hard. Suggest that crews start asking ATC at small airports to provide vectors to the Approach being used to back up the Visual when in night VMC conditions; as a means to improve the level of safety; even if it means that ATC might have to work a bit more.
Air carrier Captain descending on a Visual Approach to ABE reported they received a Terrain Alert.