The statute gives parcel owners a wide latitude in setting formulas for assessment but both the statute and the courts emphasize "fair and equitable" when determining maintenance assessment allocations.  I think you may have difficulty proving that a short term rental of a residential parcel adds more traffic than any other type of residential parcel with the same number of residential units on the parcel.  Compare a parcel with one residential unit occupied by owners with three cars and each car owner travels to and from work daily with a parcel rented by the day with three cars arriving and leaving each day. More traffic for one or the other?  Similarly, one "long term" residential owner may have only one car while another may have several.  One can assume that the owner with more cars will add more traffic than an on owner with only one. Yet each are "long term" owners.  Is it reasonable, fair and equitable to adopt an assessment scenario based upon the number of cars an owner has?  Also, in that scenario a long term owner with multiple cars may add more traffic than a short term rental where only one car arrives and leaves.  I would recommend caution when trying to concoct a fair and equitable assessment formula based on a difficult to prove assumed volume of traffic. Also keep in mind that road associations may only consider road maintenance costs not the perceived nuisance of short term rentals.   

So, can it be done? Sure. Is it a court enforceable assessment that is prudent to commit the association's funds to enforce? Consider that question carefully.

Paragraph 5 of Title 23 Section 3101 - .....The determination of each owner's share of the total cost must be fair and equitable and based upon a formula provided for in the road association's bylaws or adopted by the owners at a meeting called and conducted pursuant to this section......  

Keep in mind that these are my personal opinions but I for one would not waste money on obtaining a legal opinion on this matter. Just sayin....