Tag - NOx

Evaluating the Impact of PTI on Road Safety and Economy in Turkey (1990-2022)

The Institute for Economic Research and Consulting GmbH recently published a detailed study evaluating the efficacy of Periodic Technical Inspections (PTI) on road safety and economic outcomes in Turkey, covering data from 1990 to 2022. This comprehensive analysis, spearheaded by Prof. Dr. Wolfgang H. Schulz and his team, delves into the multifaceted impacts of PTIs, employing robust datasets and econometric models to provide insightful conclusions.

Aim and Scope / The primary objective of the study is to ascertain the effectiveness of PTIs in enhancing road safety and mitigating economic losses associated with traffic accidents in Turkey. By leveraging extensive datasets and various analytical methods, the study offers a thorough examination of how periodic vehicle inspections contribute to reducing road accidents and improving economic outcomes.

Methodology / The study employs four distinct methods to evaluate the impact of PTIs:

  • Literature Analysis: A comprehensive review of existing research on the relationship between vehicle inspections and road safety.
  • Visual Analysis: Examination of trend developments over time to identify any significant changes.
  • Autoregressive Processes: Analysis to detect patterns and shifts in the data.
  • Chow Test: Statistical verification of structural breaks in the dataset, particularly around significant policy changes such as the introduction of PTIs in 2008.

Key Findings / The study's literature analysis reveals a generally positive correlation between PTIs and improved road safety. Significant reductions in accidents and fatalities have been observed in regions implementing stringent vehicle inspection regimes. Notably, the analysis of PTI implementation in Turkey indicates a structural break in 2008, suggesting that the introduction of PTIs significantly altered the trajectory of road safety metrics. On average, the share of deaths related to fatal accidents is 0.03766. With this, 5,033 deaths could be avoided. The share of injuries per fatal accident is, on average, 1.6429, which means that 219,498 injuries could be avoided.

Trend Analysis / From 1990 to 2022, the dataset provides a comprehensive overview of road traffic accidents, fatalities, and injuries in Turkey. The analysis indicates a marked reduction in fatalities and injuries post-2008, despite an initial increase in the number of accidents. This paradoxical trend underscores the efficacy of PTIs in mitigating the severity of accidents.

Economic Impact / The economic analysis within the study highlights significant cost savings attributed to the implementation of PTIs. The average annual savings amount to approximately 1.5 billion TL, with total savings from 2008 to 2022 estimated at 22.48 billion TL. These savings underscore the economic viability of PTIs, reinforcing their role in reducing the financial burden of road accidents on society.

Regression Analysis and Chow Test / The regression models demonstrate strong relationships between the implementation of PTIs and improvements in traffic safety. The Chow test confirms the presence of a structural break in 2008, validating the significant impact of PTIs on road safety metrics in Turkey.

Conclusions and Recommendations / The study concludes that PTIs have been highly effective in improving road safety and delivering substantial economic benefits in Turkey.

Key recommendations include:

  • Enhanced PTI Frequency and Coverage: Increasing the frequency and coverage of PTIs to capture and mitigate vehicle deficiencies more effectively.
  • Integration with Other Safety Measures: Incorporating PTIs into a broader road safety strategy that includes driver education, infrastructure improvements, and stricter enforcement of traffic laws.
  • Longitudinal Studies: Conducting further research to track the long-term effects of PTIs on road safety and economic factors.
  • Comparative Analysis: Benchmarking Türkiye's PTI practices against other countries with similar traffic conditions to refine and improve inspection protocols.
  • Policy Adaptation: Updating PTI criteria and techniques to address new safety challenges and technological advancements in automotive design.

Future Implications / The success of the PTI program in Turkey suggests its continued importance in maintaining and enhancing road safety. Ongoing adaptation and integration with other safety measures will be crucial in sustaining and building on the improvements achieved thus far.

For more detailed information, the full study can be downloaded here.

Evaluation of African Road Safety Action Plan Shows Mixed Results

CITA has published new findings from a comprehensive study evaluating the African Road Safety Action Plan, developed by the United Nations Economic Commission for Africa (UNECA). The study, conducted by researchers Dominique Mignot, Laurent Carnis, Eduard Fernandez, Davide-Shingo Usami, and Ruth Welsh, highlights the critical challenges and progress in road safety across the African continent.

The research, which aims to contribute to the improvement of road safety in Africa, reveals that despite some advancements, significant challenges remain. The mid-term evaluation of the UNECA Action Plan indicates that the expected results are not being fully realized, with progress being uneven across different pillars of road safety.


  • Road Safety Management: The study identifies weaknesses in road safety management, including poor institutional organization and coordination, inadequate policy implementation, and insufficient funding. Only a few countries like Burkina Faso and South Africa show relatively good performance, while many others lag behind.
  • Safer Roads and Mobility: The implementation of road safety audits and inspections is progressing slowly. Few countries have developed technical guidelines for road safety audits and inspections, which are crucial for improving road infrastructure safety.
  • Safer Vehicles: While vehicle inspection is widespread, the quality and regional spread of inspections are inconsistent. The study recommends encouraging the importation of safer vehicles through the application of standards and improving the roadworthiness of both new and used vehicles.
  • Safer Road Users: There has been some progress in promoting road safety among young people, but much work remains. The use of child restraints and education on safe road user behavior are areas needing significant improvement.
  • Post-Crash Response: The capacity for post-crash response, including emergency medical services and trauma care, is generally inadequate. The study emphasizes the need for better-equipped ambulances, improved emergency medical services, and the development of trauma care facilities.


The study proposes several recommendations to enhance road safety in Africa:

  • Strengthen the institutional framework and allocate adequate resources for road safety policies.
  • Develop consistent and systematic data collection systems to inform public policies.
  • Promote the use of child restraints through legislation and public awareness campaigns.
  • Improve the technical capacity for road safety audits and inspections.
  • Ensure the availability of quality spare parts and a network of qualified repair and maintenance workshops.
  • Enhance cooperation with non-governmental organizations (NGOs) and the private sector.

Eduard Fernandez, representing CITA, emphasized the importance of these recommendations, stating, "Effective implementation of these measures is crucial for saving lives and improving road safety across Africa. CITA remains committed to supporting African countries in their efforts to enhance road safety."

For more detailed information, the full research report can be accessed here.

CITA Webinar “Validation of a Method to Test NOx Emissions”

The webinar, hosted by CITA and the Joint Research Centre (JRC), took place on June 19th on the CITA Zoom channel with over 80 participants. The discussion focused on the collaborative project between the two organizations, aimed at validating a new method for testing nitrogen oxide (NOx) emissions during Periodic Technical Inspections (PTI) in the EU.

Mr. Jacopo Franzetti, Project Manager for Scientific Research at JRC – European Commission, and Mr. Max Holtermueller from DEKRA together with Mr. Thomas Ost, leader of the CITA Taskforce on Emissions, led the presentations. They highlighted the importance of NOx, its formation and reduction, and the scope, the method and results of the project.

Why Focus on NOx? Nitrogen oxides (NOx) are harmful pollutants with severe health impacts. NOx is a strong oxidizing agent that can cause respiratory issues, aggravate other pollutants' effects, and lead to diseases like asthma, bronchitis, and cardiovascular problems. A significant improvement in air quality in Europe has been noted, but NOx levels still exceed WHO guidelines, contributing to premature deaths. NOx primarily forms at high temperatures in the presence of sufficient oxygen, commonly occurring under high engine loads. This poses a challenge for PTI, as controlling these conditions during inspections is complex.

The Project. The JRC has developed a streamlined method for measuring NOx emissions during the PTI of modern Euro 6d diesel light-duty and Euro VI heavy-duty vehicles. This aims to identify malfunctions in Selective Catalytic Reduction (SCR) systems, crucial for reducing NOx emissions. The objective of the project was to validate a NOx monitoring method tailored for PTI in the EU, focusing on modern diesel vehicles under real-world conditions. Various CITA members participated, testing vehicles across different EU countries to account for diverse PTI systems.

The Results. 161 vehicles from various countries were tested, encompassing a wide range of mileages and ages. Key findings include:

  • Vehicle Age and Mileage:  A very wide range of vehicles were tested, with mileages ranging from 0 to 347.000 km.
  • NOx Emissions: Average NOx emissions were 26 ppm in the first 30 seconds, with significant variations among different participants and vehicle conditions.
  • Feedback: Participants rated the method's feasibility, integrability, and time effort on a scale from 1 to 5, with average scores indicating moderate satisfaction. Challenges included difficulty in warming up vehicles and software/hardware issues.

Conclusion. The validated method is suitable for modern diesel vehicles with SCR catalysts but not for those without. While the method is generally simple, integrating the warm-up process into PTI remains a challenge. Further optimization and precise specifications for the warm-up process are necessary. CITA's Task Force on Emissions is preparing a detailed report on the project's findings, expected to be published by August/September. Additionally, a survey on driving practices during PTI will be conducted between CITA members.

CITA remains committed to supporting the method's further development and implementation.