Diesel on carriageway

I am regularly noticing an appreciable trail of diesel fuel spillage along Lower Church Road, Primate Road, Warsash Road and round the St Margaret's roundabout towards Fareham. I have noted this now on four or five separate occasions over the last three weeks, being particularly noticeable when the road is wet. This is a dangerous hazard, particularly for motorcycles as it will cause loss of grip if either not seen or not expected by the rider. Potential to cause injury. The route is always the same and (maybe coincidentally) is part of a bus route. More consideration for other road users needed when fuelling diesel vehicles to avoid overfilling and spillage.