Relevance of indicator to greenhouse gas emissions
In 2022, the transport sector accounted for 17% of Northern Ireland’s
greenhouse gas emissions, with cars accounting for 11%. Demand for
travel by car is expected to increase, so in order to reduce emissions
the demand will need to be met more efficiently. This indicator
considers how efficiently the demand for transport by car has been met,
and how that has changed over time.
Any known issues or limitations
Estimates of greenhouse gas emissions have an inherent uncertainty
due to uncertainty in the underlying activity data and emissions
factors. For more information see:
Northern
Ireland Greenhouse Gas Inventory 1990 to 2023
The Driver and Vehicle Licensing Agency (DVLA) database can be
regarded as being virtually complete in terms of the number of licensed
vehicles and vehicles with a SORN. However, there will be some errors in
some of the specific details of individual vehicles.
The DVLA carry out regular Traceability Surveys which look at whether
it is possible to trace the owner of any given vehicle and check what
details on the database are inaccurate. They estimate that every
variable is correct for roughly 89% of the registered vehicles. The
remaining 11% of vehicles will have an error in at least one of the
fields. Of the overall total, about 4% have wrong details that make it
impossible to trace the registered keeper of the vehicle (often caused
by keepers not providing DVLA with updated details when they move or
dispose of the vehicle).
Most of the inaccuracies in the database are with the less critical
variables, such as colour, though some will affect the statistics
published here (e.g. by having the wrong CO2 g/km emission value or the
wrong wheelbase). Department for Transport estimates that under 2% of
vehicle records have an inaccuracy in one of the variables used for the
statistics published.
There have been a number of major changes to the Vehicle Excise Duty
system which should be taken into account when considering trends over
time. From March 2001, cars were taxed according to the emissions
emitted by the vehicle. There were six bands (A to F). In March 2006, a
new emissions band (Band G) was introduced. From April 2009 the seven
emission bands were increased to 13 (A to M) and redefined. For cars
registered for the first time from April 2017 onwards, a flat Standard
Rate applies (except for zero emissions cars which remain zero rated)
after the first year. Cars with a list price in excess of £40,000 incur
a supplement on their standard rate for the first five years in which a
standard rate is applied. These changes in rates may have influenced car
choice. For further details see:
Vehicle
Excise Duty
When a car is registered for the first time, a CO2 emissions figure
is reported for monitoring purposes. The method used to determine
emissions has changed over time. Up until September 2018 cars registered
for the first time reported a New European Driving Cycle (NEDC) figure.
From September 2018, the Worldwide harmonised Light vehicles Test
Procedure (WLTP) was introduced, with a transition period allowing cars
to report either a NEDC or an equivalent NEDC figure (or e-NEDC figure)
i.e. one calculated based on the results of a WLTP test. WLTP became the
reported figure used when cars registered from April 2020 and from 2021
will be the only figure available for new cars. Whilst the e-NEDC figure
was designed to be broadly ‘equivalent’ with an NEDC figure, the new
WLTP figure is typically about 20% higher for petrol and diesel
cars.
Vehicle
Licensing Statistics: Notes and Definitions