The Effect of Barzan Highway Improvements on the Traffic Stream Parameters


  • Nareen Nareen Newzad M-N Highway and Bridge Engineering Department, Technical College of Engineering, Duhok Polytechnic University, Duhok, KRG – Iraq.
  • Sheimaa Ibrahim Mohammed Highway and Bridge Engineering Department, Technical College of Engineering, Duhok Polytechnic University, Duhok, KRG – Iraq.
  • Mudhafer Hameed Selman Highway and Bridge Engineering Department, Technical College of Engineering, Duhok Polytechnic University, Duhok, KRG – Iraq.



The rapid economic growth in Duhok City has resulted in high traffic volumes, increased the flow of stream traffic, and decreased the speed of running. Therefore, over the last few years, many roads have suffered from non-uniform traffic flow, traffic jams, and increased traffic accidents. There are several causes for the development carried out by the Duhok Governorate on the Barzan Highway, where signalized at-grade intersections were replaced by bridges and tunnels to prevent conflicts between vehicles on the highway. This study will evaluate how much improvement has been made to the Barzan Highway's main parameters after the improvements have been made. Based on the results of the study, it can be concluded that the underpasses have contributed to the creation of safer roads by reducing the accident rate by 47%, decreasing the average traffic flow from west to east (Imam Hamza underpass to Farmanda underpass) by 32%, and decreasing the average traffic flow from east to west by 10%, reducing travel time from west to east by 48%, and from east to west by 45%; moreover, the density improved from west to east by approximately 60%, while from east to west by 63%.


Download data is not yet available.


C. Nacional, “The Effect Of Speed, Flow, And Geometric Characteristics On Crash Rates For Different Types Of Virginia Highways,” J. Petrol., vol. 369, no. 1, pp. 1689–1699, 2000.

T. F. Golob and W. W. Recker, “A method for relating type of crash to traffic flow characteristics on urban freeways,” Transp. Res. Part A Policy Pract., vol. 38, no. 1, pp. 53–80, 2004, doi: 10.1016/j.tra.2003.08.002.

D. Lord, A. Manar, and A. Vizioli, “Modeling crash-flow-density and crash-flow-V/C ratio relationships for rural and urban freeway segments,” Accid. Anal. Prev., vol. 37, no. 1, pp. 185–199, 2005, doi: 10.1016/j.aap.2004.07.003.

M. Gaudry and K. Vernier, “Effects of road geometry and surface on speed and safety,” Accid. Anal. Prev. 34.3, vol. 34, no. November 1998, pp. 357–365, 2002.

A. Ceder and M. Livneh, “Relationships between road accidents and hourly traffic flow-I. Analyses and interpretation,” Accid. Anal. Prev., vol. 14, no. 1, pp. 19–34, 1982, doi: 10.1016/0001-4575(82)90004-5.

et a D. Glavić, “Contribution To Accident Prediction Models Development For Rural Two-Lane Roads In Serbia Abstract.” 2016.

G. Technica, “Integrated Surveying for the Archaeological,” vol. 11, no. 2, pp. 39–50, 2016, doi: 10.21163/GT.

J. L. Martin, “Relationship between crash rate and hourly traffic flow on interurban motorways,” Accid. Anal. Prev., vol. 34, no. 5, pp. 619–629, 2002, doi: 10.1016/S0001-4575(01)00061-6.

Q. Meng and X. Qu, “Estimation of rear-end vehicle crash frequencies in urban road tunnels,” Accid. Anal. Prev., vol. 48, pp. 254–263, 2012, doi: 10.1016/j.aap.2012.01.025.

P. C. Anastasopoulos and F. L. Mannering, “A note on modeling vehicle accident frequencies with random-parameters count models,” Accid. Anal. Prev., vol. 41, no. 1, pp. 153–159, 2009, doi: 10.1016/j.aap.2008.10.005.

J. Kononov, B. Bailey, and B. K. Allery, “Relationships between safety and both congestion and number of lanes on urban freeways,” Transp. Res. Rec., no. 2083, pp. 26–39, 2008, doi: 10.3141/2083-04.

a Baruya, “Speed-accident relationships on European roads,” 9th Int. Conf. Road Saf. Eur., vol. 1, 1998.

L. Aarts and I. Van Schagen, “Driving speed and the risk of road crashes: A review,” Accid. Anal. Prev., vol. 38, no. 2, pp. 215–224, 2006, doi: 10.1016/j.aap.2005.07.004.

S. Roshandel, Z. Zheng, and S. Washington, “Impact of real-time traffic characteristics on freeway crash occurrence: Systematic review and meta-analysis,” Accid. Anal. Prev., vol. 79, pp. 198–211, 2015, doi: 10.1016/j.aap.2015.03.013.

T. F. Golob, W. Recker, and Y. Pavlis, “Probabilistic models of freeway safety performance using traffic flow data as predictors,” Saf. Sci., vol. 46, no. 9, pp. 1306–1333, 2008, doi: 10.1016/j.ssci.2007.08.007.

E. De Pauw, S. Daniels, M. Thierie, and T. Brijs, “Safety effects of reducing the speed limit from 90 km/h to 70 km/h,” Accid. Anal. Prev., vol. 62, pp. 426–431, 2014, doi: 10.1016/j.aap.2013.05.003.

D. Shefer, “Congestion, air pollution, and road fatalities in urban areas,” Accid. Anal. Prev., vol. 26, no. 4, pp. 501–509, 1994, doi: 10.1016/0001-4575(94)90041-8.

M. Hossain and Y. Muromachi, “Understanding crash mechanism on urban expressways using high-resolution traffic data,” Accid. Anal. Prev., vol. 57, pp. 17–29, 2013, doi: 10.1016/j.aap.2013.03.024.

B. Ostendorf and A. E. Retallack, “Current Understanding of the Effects of Congestion on Traffic Accidents,” Int. J. Environ. Res. Public Health, pp. 1–19, 2019.

C. Wang, M. Quddus, and S. Ison, “A spatio-temporal analysis of the impact of congestion on traffic safety on major roads in the UK,”, vol. 9, no. 2, pp. 124–148, Feb. 2013, doi: 10.1080/18128602.2010.538871.

S. Moridpour, “Evaluating the Time Headway Distributions in Congested Highways,” J. Traffic Logist. Eng., vol. 2, no. 3, 2014, doi: 10.12720/jtle.2.3.224-229.

“Directorate of Statistics in Duhok”.

“Municipality of Duhok”.

“Dohuk Governorate Traffic Directorate, Department of statistical and planning.”



How to Cite

Nareen Newzad M-N, N., Ibrahim Mohammed, S., & Hameed Selman, M. (2024). The Effect of Barzan Highway Improvements on the Traffic Stream Parameters. Academic Journal of Nawroz University, 13(1), 176–185.