You can apply for a dropped kerb using the application pack on this webpage. Once you have paid the inspection fee, which is non-refundable, Hounslow Highways will review your application and will arrange for an engineer to carry out an inspection.
If they determine that a dropped kerb would be acceptable with respect to road safety, you will receive a quote for it to be installed.
Each dropped kerb is priced based on the measurements and materials involved, as well as the cost of moving anything that would block the new access, such as a lamppost or a water pipe.
Some dropped kerbs require planning permission, for example outside a flat or in a conservation area. While planning permission should be applied for after you have received a response from Hounslow Highways, it is advisable to refer to the application pack beforehand to know if this requirement would affect you, as it lengthens the process and there is a further fee involved.