Diesel urban buses as well as garbage trucks are part of the particulate emissions sources that affect the city air quality. Retrofit programs have developed Diesel particulate filters approaches in order to limit the particulate emissions in the cities. To fit the particular duty driving cycle requirements, a new active Diesel particuiate filter (DPF) system is proposed to control the filters regeneration. The DPF system process is based on a global thermal management of the volume of filtration, using an electronic control unit, SiC-based filters units, an oxidation catalyst, an exhaust port fuel injector placed in front of the oxidation catalyst and an automatic valves system to control automatically the volume of filtration. An additional exhaust heat injection, based on hydrocarbon catalytic combustion over the oxidation catalyst placed in front of the filters units, allows heating up the filters independently, according to the the insulating valves configurations. The DPF system was evaluated under the French national program on urban buses and refuse trucks. According to the UTAC certification, it shows a high efficiency in exhaust emissions reductions: - in the case of retrofit applications, the EURO II Renault AGORA bus, after 11,000 km+ on the urban line, showed very high emission reductions (more than 90 %) on CO, hydrocarbons and particulates over a representative urban bus cycle. In addition, the UTAC measurements performed on the EURO III RENAULT Trucks Premium 320 DCI 11 engine for refuse trucks, showed similar reduction levels on CO, hydrocarbons and particulates which remain far below the present EURO III and the future EURO IV standard limits. Reliability, durability and efficiency were demonstrated in the French national program in the real field tests (urban buses and refuse trucks). In parallel, to eliminate accumulated ash arising from the lubricant consumption and engine operation, a cleaning procedure is necessary, and a specific machine and maintenance protocol have been developed. At the moment, it is recommended to clean filters units between 70000 and 100000 km, which amounts saying between 12 to 18 months of operation. New developments and improvements of the DPF system are going on, particularly in the association with a fuel-borne catalyst to limit fuel injection quantities during the forced filters units regenerations.