Sir, We are deeply disappointed at the decision by Mike Penning to allow trials of longer lorries.

The proposed trials will allow about 1,800 lorries of up to two ­metres longer to operate across the UK, for up to 10 years.

The research previously undertaken by DfT demonstrated that full introduction of longer lorries would have a devastating impact on the prospects for rail freight growth in the retail sector. Concerns have also been raised regarding safety, the ability to utilise the additional space, and the impact on small haulage companies.

The DfT's decision to proceed with the trials is a blow to the rail freight sector, and raises questions about this government's commitment to greener transport. We will be pressing to ensure the trial will be properly representative, and will address the major concerns associated with these vehicles.

Maggie Simpson, policy manager, Rail Freight Group