DAL Controller described a Runway 13L incursion event noting ATC has made multiple notifications to the Airport Manager concerning the confusion regarding the subject hold short lines.

Narrative

I was giving OJT on Local Control West position at Dallas Love Field. The trainee was departing aircraft off Runway 13L when I looked over to Runway 13R to see a B737 landing just past the intersection of Taxiway C6. I noticed out of the corner of my eye a Beechjet taxiing just past the hold short line for Runway 13R. I instructed the trainee to get the aircraft out of the hold short area. We did not receive a response from the pilot. We then told Ground Control to get the aircraft out of the hold short area. We saw the pilot of the Beechjet taxi clear of the hold short lines. There are numerous taxiway closures on the route to the runway for the aircraft due to construction. I would cut down the phraseology on taxiing aircraft for one. Also; put on the ATIS about the new hold short lines for Runway 13R to remind the pilots. The third thing I would recommend is to put up some red lights or reflectors at the hold short lines so the pilots can easily see the 'new' hold short lines. The Manager at Love Field has told Airport Operations about this problem on numerous occasions and nothing has been done.