Whilst the target for many on flyer talk is against UK APD many countries have departure taxes and had them long before APD was introduced in the 1990s.

The uise of capital cities to determine the band was indeed for simplicity.

When the 4 bands were introduced in 2009 the distances were <2000miles, 2001-4000, 4001 - 6000 and 6001+ miles

Ir would have put some popular UK holiday destinations such as Florida in Band C rather than B if individual distances were used rather than capital to capital.

And whilst APD only applies to flights leaving the UK there are still ways around paying it if you route properly..

Charges like BA carrier surcharges have a bigger impact than APD on fares.

I have just booked an ex CDG routing to the US

Fare - €804

Airport fees and proper taxes = € 209.53

BA Carrier Surcharge = € 326 (and only 2 short hails are on BA - from/to CDG)