Staff sickness levels among driving test and vehicle licensing staff are "worrying", says a government watchdog.
There was higher than average sick leave among driving examiners
Driving Standards Agency (DSA) staff averaged 13.1 days off sick in 2005 and 13.7 days in 2006, the National Audit Office report said.
Driver and Vehicle Licensing Agency (DVLA) staff took an average 14 days off sick in 2005 and 13.1 days in 2006.
The NAO also said the two agencies were "performing well". Civil service staff took around 9.8 days off sick a year.
This compared with an average six days a year taken by staff in the private sector.
The Department for Transport's own target is 7.5 days sick per employee by 2010.
Most DfT agencies remained some way off the 2010 target, and only the Highways Agency met its own 2006 target which was 7.9 days, the government spending watchdog found.
NAO head Sir John Bourn said: "Today's report paints a mixed picture of sickness absence in the Department for Transport and its agencies.
"While some parts of the department compare favourably against other public and private sector organisations and all parts of the department appear to be proactive in managing sickness absence, the high rates in the customer-facing agencies of DVLA and DSA are worrying."
A DfT spokeswoman said that the report recognised the two agencies were "successfully managed businesses" despite their higher than average sickness levels.
"The DVLA and the DSA are committed to reducing sickness rates. We are working to support people who are genuinely sick while addressing underlying causes and improving procedures to minimise absence," she said.
The DfT pinpointed to a range of reasons for the sickness levels, including an increasing volume of work at the DVLA.
"The DSA's work makes it difficult to benchmark against other organisations," the spokeswoman added.
"The nature of the driving examiner's job makes it harder for them to work if they are not fully fit, and there is very little opportunity for them to be deployed to other duties if they are not fit to conduct tests."
She said the proportion of musculoskeletal injury cases among examiners was comparatively high.
Although it was not known if this was directly work-related, the DSA had introduced physiotherapy and prevention programmes, she added.