Average is around 22kmh depending on the wind

but the speed range can be from 6kmh - 40kmh and the commute takes in all sorts of country and urban settngs, cycle track, grass, roads, footbridge, pavement, rotted pavements and rotted roads.
I also carry a backpack thats 10kg-12kg, (I must have my tools! Also tried panniers and hated them). The bike has a big 12v battery on it to power the 50 watt halogen and another battery in the back pack for the 20watt helmet light. I'm nuts about lights had have about 3 other lighter "back up" lights on the handlebars. I have all my spare clothes, work clothes and clean cycling clothes for the return home, spare food, emergency stuff etc.
I'll be sorted when the Zombie holocust kicks off!
The bike is a big old giant mountain bike with semi-slicks thrown on and bomber forks for the huge earthquake made potholes that infest NZ, Dragging the monster up hills gives the shoulders, arms and neck a good work out ,so I'm not your typical cyclist shape!.