It is almost certainly also law enforcement activity as ensuring public safety is, no matter how they might often fail to do so, a function of the police.

The earliest Pennsylvania budget that is available online is that for FY 1969 - 1970. On page 237 (345 of the file) in the section regarding the State Police, i shows an estimated expenditure of 25,403 for FY 1968-1969 and there are references to things like them receiving, "a Motor License Fund transfer for traffic patrol activities." So the transfer has been made for at least fifty five years and I would bet that it could be shown to go back as far as the creation of the Motor License fund in 1946 if the relevant documents were readily available.

What's more, prior to the current Pennsylvania State Police, there was briefly a separate Highway Patrol within the Department of Highways that was later merged with the State Police to form the Pennsylvania Motor Police, which were later renamed back to Pennsylvania State Police. In light of that, it seems plausible to me that the constitutional amendment the created what is now Article VIII § 11(a) was written to include allowance for it to fund, "safety," with the intention of allowing for highway patrol functions to be funded from motor vehicle revenues, in keeping with their past association with the Highway Department.

A more than half-century old precedent of actual practice seems to lend credence as a matter of reality to my reading. Even if I'm wrong, all that means some combination of that the PSP must reduce their activities, other functions of the government must be reduced or new revenues my be raised elsewhere, which might in fact end up just being equivalent to increasing Motor License Fund Revenue sources to compensate for the transfer to the State Police, because no matter what governments pretend, money is still fungible.