AVP Tower Local Controller reported they issued a go-around to an aircraft on short final approach due to a vehicle crossing the runway. Reporter stated the TRACON Radar position being worked from the Tower Cab radar instead of the TRACON due to staffing contributed the event.

Narrative

Due to staffing; our operation was combined to the Tower with Approach Control in the Tower. Local was working from the; normally; Ground position. Radar was working from the; normally; Local position. Ground was at the Flight Data position. Tower/controller in charge (CIC) was providing oversight for both Approach Control and Local/Ground operations. I was Local. The runway in use was Runway 04. The VFR aircraft was inbound from the west. The winds were calm. I offered approach into Runway 10 which the pilot accepted. It is typical operation for Ground to keep control of Runway 10 as it is not frequently used; and we have higher than normal vehicle crossings on that runway. I took control of the runway and the runway bar as the visual reminder. The Ground Controller acknowledged the coordination. I had Aircraft Y holding short of Runway 04 that I instructed 'hold short Runway 04; traffic landing Runway 10'. At that point Aircraft X was short final. I was scanning to ensure the Aircraft Y held short when I heard a voice inflection from the Ground Controller. I looked up to scan Aircraft X and saw a vehicle crossing the runway. I began telling Aircraft X to go around when the Ground Controller also stated to send him around. The aircraft went around prior to crossing runway threshold. Recommendation. The first issue is the overuse of vehicles crossing the intersecting runway. It has been mentioned by inspectors and by controllers.Second issue is the over practice of Ground having control of Runway 10/28. This has caused complacency in needing coordination to cross the runway because we get used to always having control of the runway as Ground Control.The third issue is the combination of radar and Tower positions in the Tower during hours that it should not be combined. The SOP states the Tower/TRACON should NOT be combined outside of the hours of XA:00 and XI:30. This incident was at XK:30. As a result; only one CIC was providing oversight for the two areas. The radar position seemed to have moderate traffic while the Tower positions were fairly slow. As a result; it did not seem CIC was aware crossing instruction issued by Ground.