So you have discouraged unnecessary journeys, boosted awareness of public transport and challenged staff to think hard about how and why they use cars and vans.

However, there will always be a genuine need for travel by road—so how do you make those journeys greener?

This is actually the hardest part of the green equation, according to fleets.

Repeatedly, fleets with excellent green track records have focused on the driver and the vehicle, and then on cutting unnecessary journeys – but relatively few look in detail at optimising the efficiency of remaining journeys.

Many choose to leave it up to the driver/worker to be good at their job.

However, efficiency in one’s job doesn’t necessarily equate to efficiency on the road.

The Lake District National Parks Authority uses a travel hierarchy which moves employees through a logic tree, starting with ‘Is the journey necessary?’ and ending with grey fleet use as the final option.

“Over a certain mileage it is more efficient for employees to take a rental car from our supplier than to use their own,” says Martin Curry, head of property services.

Since 2009, the Lake District National Park Authority has cut CO2 emissions by 25%, with transport emissions contributing 68 tonnes of this (39%). It has also cut grey fleet usage by 75%.

Approved mileage allowance payment (AMAP) rates can incentivise grey fleet drivers to use private cars unnecessarily, says Ian Featherstone, knowledge manager at the Energy Saving Trust.

He suggests companies use mileage monitoring systems where drivers enter postcode to postcode journey details, and that they find out exactly which vehicles are being driven.

“It isn’t unusual for claimed mile-age to reduce once these systems are put in place,” he says.

For company car drivers, once vehicle usage and journeys are established this can be compared with fuelcard data, and drivers reimbursed on actual cost.

“This is where you can start to see individual vehicle and driver efficiency levels,” says Featherstone.

Technology is important to minimising mileage but it works in different ways and at different levels.

Tracking vehicles has an immediate impact on cutting mileage as drivers are more careful once they know mileage is monitored.

Routing and modelling software is becoming increasingly important in fleet optimisation. Phil Clifford, fleet and technical manager at Edmundsbury Borough Council, has joined forces with Forest Heath District Council to achieve fleet economies of scale.

He uses RouteSmart from Integrated Skills to optimise fleet movements and has so far applied it to refuse collection and street sweeping.