United Nations Environment Programme

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Tool 17: Monitoring

Monitoring is an important part of implementing your strategy. With a couple of good indicators you can follow up on whether your own work is successful or not, identifying where it is not working, and communicate your improvement to society at large.

The choice of indicators is important. An indicator can be very complex and also very basic. It all depends on how much time and effort you want to put into monitoring.

Photo: Stuart Rayner

A basic and relatively easy indicator is fuel use per ton-km for freight companies or fuel-use per passenger km for public transport companies. These indicators include numbers that you already should keep track on and are easy to compile.

Fuel use or CO2 emissions/Ton-km
Fuel use or CO2 emissions/passenger km
Fuel use or CO2 emissions/ton


Fuel use per ton-km or fuel use per passenger-km captures how efficient you have been able to delivery your goods/passengers and takes into account that your business may grow or decrease during this period without affecting your indicators.

Fuel use is also an overall good indicator on emissions such as PM, CO, HC and NOX but needs to be complemented with other indicators.

vehicleOther indicators: Average vehicle age is one good indicator; percentages of vehicles equipped with emission control technologies can be another, percentages of total fleet meeting Euro I, II, III, IV, and V standards is also a good indicator. These indicators do not give you any direct numbers on how much less pollution your fleet emits but can be very effective in communicating your progress.

Photo: Berndt Decker

Examples of other indicators:

Average vehicle age (years)
Share of vehicles equipped with emission control technologies (%)
Share of vehicles meeting Euro I, II, III IV, or V standard (%)


The calculation tool can also be used to get a rough indication on your vehicles emission per ton-km improvement as you upgrade your fleet over time.

It takes time. Over the next years you should be able to see the results in e.g. decreasing emissions/ton-km and decreasing fuel use/ton-km.