UK road transport by Greenhouse Gas Protocol


Road vehicle emissions methodology. Calculates direct carbon dioxide (CO2) emissions associated with distance travelled. Choices include vehicle type, fuel type and emissions standard. United Kingdom.


This methodology represents greenhouse gas emissions associated with the road transport in the UK. The data and calculation methodology is based on those provided in the Greenhouse Gas Protocol worksheet GHG emissions from transport or mobile sources (version 2.2), published in June 2011.

The methodology

Emissions model

The emissions methodology is based upon emissions factors which describe the rate at which greenhouse gas emissions are produced during road-based travel in relation to distance travelled. These emissions factors represent emissions associated with entire vehicles (e.g. car, motorcycle), which can be contrasted with similar transport-related emissions factors which describe emissions on the basis of individual passengers. Emissions for individual passengers can nevertheless be derived by 'sharing' vehicular emissions across all vehicle occupants, if the occupancy of the vehicle is known.

Emissions - expressed in terms of mass (e.g. kg) - are calculated by multiplying these rates (mass emitted per distance; e.g. kg CO2 per km) by a distance (e.g km) travelled.

Model data

The rate at which road transportation produces greenhouse gas emissions varies with the type of vehicle, depending on factors such as the type of fuel used (e.g. gasoline/petrol, diesel), and vehicle the fuel efficiency (i.e. the distance achieved per unit of fuel consumed) which may be related to, amongst other things, vehicle size. Therefore, emissions factors for a broad range of generalised road transport scenarios are provided.

A total of 22 specific types of road transport are represented and are differentiated by vehicle type (i.e. car, light goods vehicles, motorcycles), fuel type (gasoline/petrol, diesel, hybrid, LPG/CNG) and emissions standard. For each vehicle represented, a specific CO2 emissions factor is used to calculate CO2 emissions according to distance travelled.

Activity data required

According to this methodology, greenhouse gas emissions are directly proportional to the distance travelled, which therefore must be specified in order to make an emissions calculation.

If multiple passengers are under consideration, this number can be specified, in which case vehicle emissions are shared amongst all passengers.

Calculation and result

The returned quantities for this methodology represent CO2 emissions associated with the activity data (distance) specified.

Similar methodologies

Other Greenhouse Gas Protocol transport methodologies are available representing general transport fuel consumption, fuels consumed in specific transport contexts, freight transport, passenger/public transport, heavy goods transportation in the UK, and general road transportation in the US and other regions.

1MK2HGWSU0QG light goods vehicle, cng, less than 3.5 tonnes
NUKBL6U7XJE5 light goods vehicle, diesel, less than 3.5 tonnes
BF67PHMJMTE5 light goods vehicle, lpg, less than 3.5 tonnes
E1VMKOV48JPA light goods vehicle, lpg/cng, less than 3.5 tonnes
4RYDC89537UV light goods vehicle, petrol, less than 1.25 tonnes
M426E41ZBO79 light goods vehicle, unknown
49YN4KF6FGNQ motorbike, petrol, 125-500 cc
46HXA9B61V9H motorbike, petrol, greater than 500 cc
OK89SY21OHXQ motorbike, petrol, less than 125 cc
Y1ECUDJCD7JM motorbike, petrol, unknown
JR4CNQF5NOM0 passenger car, diesel, 1.4-2.0 litres
9S35GGAL5WS1 passenger car, diesel, greater than 2.0 litres
07H5QUD7165N passenger car, diesel, less than 1.4 litres
X4HZB9ZSXX4G passenger car, diesel, unknown
N5WU5P3KFXQG passenger car, hybrid, 1.4-2.0 litres
1SDA1UGQQ7NT passenger car, hybrid, greater than 2.0 litres
HK4F30ULQLAF passenger car, hybrid, unknown
4F0MM0LNR87I passenger car, lpg/cng, 1.4-2.0 litres
TVWKFTUX7FEY passenger car, lpg/cng, greater than 2.0 litres
XRXPRTG3371L passenger car, lpg/cng, unknown
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