Maximum flow rate at the moment is 34. When both ends are complete it will increase to 40. I haven't seen a figure for just 08 but when that end is completed at the end of the year the flow rate will be set by runway 26 which then becomes the longer back track if required. The 26 taxiway extension is only a short one and will match the take off run for 08. The taxiway extension for 08 will be 540m long but the includes the right angle curve and the additional length from that bend to the runway
Just a guess for the interim rate but I would think it will be something like 37 or 38 but as I say that is a pure guess but crucially the bottleneck where taxiway Alpha and Bravo meet by the fire station will be no more which might help the numbers as well.
