I don't believe you can decide who to assess because of funds. You need to be able to assess the risk, perhaps start with pool car use, accident rates, points on licence and start with those that are high risk . You could assess all drivers and have an approach that where they are high risk you do further assessments and training. The HSE and ROSPA have some good information on their web sites re this. It also depends on what the on line assessment is as to how to approach. My last organisation started with those who had car allowance or company vehicles and were going to address the grey fleet later. Those with company cars were easier to identify and assess regarding accidents etc. Hope this helps.

Are we not now already risk assessing??? - The irony :)

Are we really supposed to risk assess individual drivers and their foibles? I don't think so.

I cannot see that there is any good reason to RA individual drivers. Employees should provide a health questionnaire when starting work which should identify any long or short-terms ailments, employers provide driver awareness training maybe, obtain periodical copies of their licence, etc. Under normal circumstances I do not see any benefits of doing individual RAs - surely there are enough meaningless RAs in this world without adding more?

The number of miles travelled doesn't seem an unreasonable factor to use when trying to decide on the level of risk. However, given the limited information that you have provided I would agree that 'routine' individual driver RAs is probably not necessary. For our heavy fleet drivers we include driver assessment in the CPC and we also do further driver assessments if drivers keep having 'dinks'.