Buckingham Palace is advertising for a new head of travel to help cut costs and CO2 emissions for official trips by the Royal Family.
Advertised on the monarchy's website, the post pays from £55,000 to £75,000.
The palace said cost-effectiveness and green concerns had been longstanding travel considerations, but were now being emphasised more than ever.
The Royal Family carries out almost 3,000 official engagements around the UK and overseas each year.
This travel is paid for by a government grant-in-aid, which totalled £7m in 2010-11.
The head of travel will manage all trips on armed forces, commercial and foreign governments' aircraft, the royal helicopter, royal train and scheduled rail services.
The job description says the head of travel will deliver recommendations for air, road and rail travel "taking account of the programme to be accomplished, the need to minimise expenditure and CO2 commensurate with reasonable travel times and security requirements".
The role will also involve tracking travel and producing monthly reports on expenditure and CO2.
When assessing bids for flights, the head of travel must "ensure that a scheduled service option is included", says the job description.
It adds: "It is a stated objective for Royal Travel to reduce costs without compromising standards of safety, quality and security."
The successful applicant must "scrutinise existing operational and financial arrangements to determine how improved cost effectiveness can be achieved".
"He will also be required to examine all appropriate commercial alternatives that might lead to better value for money."
Applications for the post close on 18 March.