I know it's not going to be a typically packed day for the park and I don't often visit off-peak, so would taxi's and/or the shuttle bus be running tomorrow morning around 9:00?Thanks for any help

http://www.thorpepark.com/downloads/plan-your-visit/bus-950-timetable.pdfFull bus timetable as from the park site...

Indeed Benin! Buses basically come every 10 minutes, so don't worry if there's not one there when the timetable says, you'll still get to the park!