Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2025 May;32(25):15050-15065.
doi: 10.1007/s11356-025-36573-3. Epub 2025 Jun 5.

Influence of road and traffic conditions on emissions and fuel consumption of light vehicles in a real urban driving cycle

Constantin Nitoiu #  1 , Corneliu Cofaru #  2 , Mihaela Popescu  2
Affiliations
Review

Influence of road and traffic conditions on emissions and fuel consumption of light vehicles in a real urban driving cycle

Constantin Nitoiu et al. Environ Sci Pollut Res Int. 2025 May.

Abstract

Over time, international decision-making bodies have paid a special attention to the adoption of test driving cycles in the laboratory that reflect standard traffic conditions and regulations regarding the maximum limit of pollutant emissions from road vehicles to be homologated for their admittance to traffic. The proposed study examines the impact of road and traffic characteristics on pollutant emissions and fuel consumption of light vehicles in a real urban traffic cycle. The research was carried out following two scenarios, in two phases, each of them focusing on the analysis of greenhouse gas emissions mainly (CO2), nitrogen oxides (NOx), and carbon monoxide (CO) from motor vehicles with both petrol and diesel. Simultaneously, the fuel consumption of these vehicles was also evaluated. In the first scenario, the objective was to collect real data on road and traffic characteristics through tests on a carefully selected urban route in two phases: noon (light traffic) and evening (congested traffic). In the second scenario, data from both phases were used to generate two driving cycles simulating real conditions for vehicle testing on the stand; thus, four different cars were used. The research results obtained both by traveling the chosen route and by virtually traveling the same route by using real driving cycles allow a complex analysis of the interaction of different types of cars (Standard EURO 6) with the surrounding environment in traffic conditions that can lead to improve substantial effects of impacts on its various components.

Keywords: Dynamic cycles; Fuel consumption; Pollutant emissions; Real traffic; Traffic intensity.

PubMed Disclaimer

Conflict of interest statement

Declarations. Ethical approval: This is not applicable for that specific section. Consent to participate: All participants provided informed consent to participate in the study. Consent for publication: Participants who granted consent for publication are included in this research paper. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
The vehicle positioned on the dynamometer stand during laboratory tests
Fig. 2
Fig. 2
Scheme of research scenarios
Fig. 3
Fig. 3
The urban research route (4.7 km) from the centre of the city of Brașov
Fig. 4
Fig. 4
Urban cycle: a afternoon; b evening (Auto 1-Peugeot)
Fig. 5
Fig. 5
Analysis of vehicle emissions in dynamic urban mode, in the afternoon (15:00–16:00). A Vehicle 1, SIE + Three Way Catalyst (TWC); b vehicle 2, SIE + Three Way Catalyst (TWC); c vehicle 3, CIE + OC + SCR; d vehicle 4, CIE + OC + SCR (OC, oxidation catalyst; SCR, selective catalytic reduction)
Fig. 6
Fig. 6
Analysis of vehicle emissions in dynamic urban mode, in the evening. a Vehicle 1, SIE + Three Way Catalyst (TWC); b vehicle 2, SIE + Three Way Catalyst (TWC); c vehicle 3, CIE + OC + SCR; d vehicle 4, CIE + OC + SCR (OC, oxidation catalyst; SCR, selective catalytic reduction)
Fig. 7
Fig. 7
NOx distribution depending on the speed of the vehicle (afternoon time)
Fig. 8
Fig. 8
NOx distribution depending on the speed of the vehicle (evening time)
Fig. 9
Fig. 9
Analysis of average values of vehicle emissions, fuel consumption, and other parameters. a Afternoon cycle, b evening cycle
See this image and copyright information in PMC

References

    1. Ahn K, Rakha H (2009) A field evaluation case study of the environmental and energy impacts of traffic calming. Transp Res Part D: Transp Environ 14(6):411–424. 10.1016/j.trd.2009.01.007
    1. Attfield M, Schleiff P, Lubin J (2011) The diesel exhaust in miners study: a cohort mortality study with emphasis on lung cancer. J Nat Cancer Inst 104(11):869–883. 10.1093/jnci/djs035 - PMC - PubMed
    1. Bi Yuhua, Yan Jie, Shaohua L, Ben X, Lizhong S, Peng W, Xuexuan N (2023) ACS Omega 8(16):14549–14557. 10.1021/acsomega.3c00233 - PMC - PubMed
    1. Cofaru C (2007) Transport and environmental engineering. Transilvania University Press of Brașov. ISBN:978–973–598–066–5, (pp. 103)
    1. Cofaru C (2012) Environmental engineering and legislation. Transilvania University Press of Brașov, pp 80

LinkOut - more resources