TARIFFS and how to work them out.
Each trip is made up of the following;
Initial flag ( which shows on the meter when switched to hire ) is the minimum the customer is going to pay. This buys them a fixed distance or waiting time or a combination of both. This portion of the overall charge is thus made up of the three components, £ starting rate - fixed distance - waiting time
Ongoing Drops is the rate that is going to be charged after the initial flag distance. This is made up of the fare increments( 10p 20p etc) and the distance that this pre pays. This, on a normal tariff would carry on to the end of the trip but it could also go for a predetermined distance before changing again. This is called a progressive tariff, which after the initial flag distance and charge say, goes £1.50 per mile for two miles and then changes to £1.30 per mile to the end of the journey.
Waiting Time. During this ongoing drop period, waiting time is normally implemented. This normally uses the same drop value, a set waiting time rate would be used if the vehicle was stationery. ( £12 an hour relates to a 20p drop every 60 seconds. ) When the vehicle starts to move, the customer pays for waiting time, distance charges or a combination.
Waiting time / Distance Drops changeover point. This is the point when a taxi meter changes over from waiting time to charging for distance. Although you would expect the definition of waiting time is when the vehicle is stationary, it is not. The driver does not want to lose money because he is driving so this change over speed point
is the speed a vehicle has to do to earn the same amount of money the driver would be getting in waiting time, over the ongoing distance drops. If he was getting 20p every 60 seconds in waiting time, how fast has he got to drive between the onging drop points ( where he gets 20p over a certain distance) to get the same earn rate.Once this is reached, the meter changes over to distance rather than waiting time charges.
Another way of looking at it is say the tariff was £12 per hour waiting time, dropping 20p's, the meter would drop 20p ever 60 seconds to make that earn rate. Say the on going rate is £1.40 per mile, making 7 drops of 20p over that mile, one every 251.4 yards, how fast has the driver got to drive over that 251.4 yards, which is going to give him his 20p, in the equivalent time, 60 seconds? If he drives at that speed, he will earn the same as if he was on waiting time, therefore any faster, the meter changes to distance charges, thus giving him more. That works out at 8.57 mph changeover point.
If the tariff was £40 waiting and £1.40 per mile ongoing, the waiting will be dropping every 18 seconds, but to drive the 251.4 yards in 18 seconds to get the same earn rate, he would have to drive at 28.57 mph which becomes the change over point.
If the tariff was £12 per hour waiting time and £1.80 per mile ongoing, the waiting time will be dropping 20p every 60 seconds but the ongoing will be 9 drops of 195.5 yards, the vehicle speed to do the 195.5yds in 60 seconds has got to be going 6.6 mph