Captain reported a lack of taxiway lines and markings led to confusion regarding a taxiway and its proximity to the runway overrun area at the end of runway 18 at LIT airport.

Narrative

After a night landing at LIT on Runway 18 the Captain taxied past the end of the runway into the overrun area. The runway overrun areas for 18 and 22R intersect at the location and this is also shown as HS1 on the airport diagram for known for issues. The aircraft was stopped and it was determined that it would be safer to make the left turn onto the threshold of Runway 4L to continue the taxi rather conduct a 180 degree turn. The Captain made the left turn to get onto the portion of closed Runway 4L which was available for taxi; it was also the cleared taxi route from the controller. There are no yellow taxi lines or markings at the end of Runway 18 to indicate a gentle turn to the left or right to transition to either taxiway; there is only a yellow taxi line crossing the end of the runway perpendicular to the runway for aircraft to cross the runway. This was the second leg of a trip with a contract crew member that had not flown with this Captain for 77 days. Because of the lack of recency with this crew pairing; the Captain was distracted with monitoring the contract crew members actions. There are no yellow taxi lines or markings at the end of Runway 18 to indicate a gentle turn to the left or right to transition to either taxiway. There is a yellow taxi line crossing the end of the runway perpendicular to the runway for aircraft to cross 18/36. Runway 4L is closed except to taxi across and is not lighted at night. This taxi route crosses the approach end of Runway 4L. This occurrence happened at night.