Are signs and sign hardware general fund items?

Yes, traffic control is a general fund item, since signs are approved by the Town Board. Work Zone Signs may be purchased under the highway fund, as they are authorized by the Highway Superintendent, but many towns just keep all signs under the General Fund. The specific account numbers are: A-3310 (Traffic Control), 3320 (On street parking) or 3397 (Traffic Control, Equipment and Capital Outlay). This information comes from the Office of the State Comptroller's Accounting and Reporting Manual, which can be found online:

NYS Office of the State Comptroller, Accounting and Reporting Manual (PDF)