Each year when the state collects tax revenue, it does so with the purpose of spending it in beneficial ways within the states. how do politicians decide to spend tax-payer money within the state? what criteria might they use in setting these priorities?

They will most of the time look thought the main roads and go to fix the roads or decide on putting stuff like fountains or play grounds down if the area doesn't have to much of stuff near them.

but mainly they'll spend the money on necessary things like infrastructure and roads.
for the roads and infrastructure idea they'll go and look at certain heavily used roads every  20 years or so and they'll then go and if they need work they work on them if they dont they'll pick a different one.same for buildings

hope this si what yoru looking for and if not im sorry have a good day.