Shivraj - I use two methods of costing this out. One is the popular average cost method - 3.50 divided by 2 (considering both pick up and drop) equals 1.75, which is then divided by 110. However, this is expensive since the actual number of trips the transporter makes is closer to 2 per drop (one to go to the pick-up point and then return to the office, and the reverse at the drop). So, it's up to you to decide if you want to divide the monthly bill by 4 trips or 2.
I prefer a 'real-time' method - each employee logs in the kilometers for all times, for a period of 30 days, and I reconcile the cost against each employee at the end. This allows me to reconcile the cost against each employee so I can put in place limits for transport or transport boundaries/restrictions to hiring managers, managing with a lower transport budget.