The owner of Southampton’s container terminal is aiming to increase rail’s market share to 40% by 2026.
That would represent a near-doubling in just three years and the largest proportion of rail freight from Southampton docks in modern times.
DP World is extending its financial incentive for customers, to switch from road to rail, until the end of next year.
It charges a “modal shift levy” of £10 on every full container passing through the port.
Freight owners who move their containers to rail for journeys of up to 140 miles (225km) receive £80 for each box.
Those travelling more than 140 miles by rail see the £10 levy refunded.
The aim is to make shorter distance rail travel more viable, particularly to large distribution hubs in the Midlands, that have previously mostly been reached by lorries heading from the south coast on the M3 and A34.
Since the programme launched in September 2023, the share of rail freight at Southampton has risen from 21% to 30%.
It has led to the launch of four new daily rail services, taking the total number of weekly trains to 172. Each train is up to 2,460ft (750m) long.
DP World said the scheme would help take 300,000 truck journeys off the roads each year.
It said the scheme had saved 6,400 tonnes of carbon dioxide (CO2) emissions in the first six months, equivalent to more than the entire CO2 output from the container terminal.
John Trenchard, vice president of UK commercial and supply chain at DP World, said: “We believe that we can target a 40% share for rail in 2026.
“At a time when customers face multiple challenges, including geopolitical uncertainty, increased regulatory risk, and the urgent need to decarbonise supply chains, our modal shift programme has proved highly attractive.”