Ireland is amongst the worst offenders in Europe when it comes to lorry journeys with an empty trailer - a practice that environmental campaigners say contributes to needless carbon emissions, congestion, and wasted labour.
According to analysis from Eurostat, the data wing of the European Commission, around one-fifth of the total road freight transport kilometres in the EU in 2020 was carried out by empty vehicles.
Cyprus recorded the highest share out of the EU member states for which data are available, with 44% of kilometres by empty vehicles, followed by Ireland and Austria at 34%.
Belgium reported the lowest share out of the member states for which data are available at 6%, followed by Denmark at 8%, Eurostat said.
The data show that empty journeys are more prevalent in domestic transport where the distances journeyed are typically much shorter, the data body added.
Ireland's empty journeys by lorries is far higher at home compared with its drivers travelling internationally, the data show.
The practice should be discouraged as part of plans to tackle global emissions, say environmentalists.
According to the Paris Process on Mobility and Climate (PPMC), which was formed after the landmark Paris Accords climate change pact at the United Nations Cop21 summit in 2015, truck transport accounts for about 25% of global transport energy use.
"Every year American trucks travel empty for 50 billion miles, 28% of their total mileage, and in Europe a quarter of containers on the road are empty. Empty runs have high economic costs due to the wastage of fuel, time, labor, and traffic congestion involved. The UK transport industry could save over 40 million miles of empty journeys by making use of spare vehicle capacity," the body claims.
PMCC says that trucks, buses and coaches produce about a quarter of CO2 emissions from road transport in the EU and some 5% of the EU’s total greenhouse gas emissions – a greater share than international aviation or shipping.
"Making use of spare vehicle capacity could cut UK carbon emissions by as much as 8% and contribute to a more sustainable transport industry," it says.
Technology is advanced enough that it could match firms with empty trucks that are available as a way of cutting down needless trips, the PMCC says.
By reducing empty trips, freight efficiency could be improved, leading to several co-benefits such as reduced logistics cost, reduced congestion, and reduced carbon and air pollutants.
Poor air quality, of which diesel and petrol emissions are a leading culprit, contributes to 1,300 needless deaths a year in Ireland, statistics have shown.
The Irish Heart Foundation called on the Government to implement stronger air quality regulations as a matter of urgency.