THE WIDESPREAD DETECTION OF AIR POLLUTION ACTIVE COMPOUNDS, INCLUDING NOX AGENTS, IN URBAN AND SUB URBAN TUNNELS IS RAISING PUBLIC HEALTH CONCERNS. AS A RESULT, THERE IS GROWING INTEREST IN THE DEVELOPMENT OF INNOVATIVE TECHNOLOGIES TO EFFICIENTLY TRANSFORM THESE COMPOUNDS TO NEUTRAL COMPONENTS. THIS PAPER DEALS WITH THE RESULTS OF REDUCING NOX LEVELS REGISTERED BEFORE AND AFTER THE RENOVATION WORK OF THE ‘‘TOWHID’’ TUNNEL IN TEHRAN, IRAN. THIS TUNNEL CONSTRUCT BASE ON ITA STANDARD. THE RESULTS OF THIS PAPER SHOW EFFICIENT ABATEMENT OF POLLUTANTS BY THE PHOTO CATALYTIC TREATMENT OF THE TUNNEL VAULT WITH A CEMENT-BASED PAINT, AS EVIDENCED THROUGH THE LOWER CONCENTRATIONS FOUND AFTER THE RENOVATION. THE DURATION OF THE MONITORING CAMPAIGNS PERFORMED SEEMS TO BE CONSIDERED SIGNIFICANT FROM THE STATISTICAL POINT OF VIEW, UNLIKE ALL PREVIOUS EXPERIMENTS WHICH WERE CARRIED OUT ON THE PHOTO CATALYTIC MATERIALS. THIS RENOVATION UNIQUE TECHNOLOGY CAN PROVE OUT TO BE A VERY USEFUL REFERENCE FOR THE WIDE PROGRAM FOR A SUSTAINABLE UPGRADING OF TUNNELS IN IRAN, ACCORDING TO THE DIRECTIVE 2004/54/EC ON ROAD TUNNEL SAFETY. FINALLY FOR MODIFIED PHOTOCATALYST- SEMENT BASE WE SHOULD RESPECT TO THIS CRYSTAL NETWORK PATTERN. WE WILL SHOW THAT PHOTOCALYST-SEMENT BASE CAN BE MODIFIED BY USING P 123 WITH IPA SOLUTION BECAUSE THE PHOTOCALYST-SEMENT CONSTITUTION WILL BE VERY UNIFORM AND THE CRYSTAL NETWORK PATTERN WILL BE NO CHANGE.