Improvement of Curvature Change Rate (Parameter) in Two-Line Rural Roads


  • Lina Bertulienė Department of Roads, Faculty of Environmental Engineering, Vilnius Gediminas Technical University, Vilnius, Lithuania
  • Romas Girdvainis Closed joint-stock company “Realprojekt”, Vilnius, Lithuania
  • Lina Juknevičiūtė-Žilinskienė Joint-stock company “LITGRID”, Vilnius, Lithuania
  • Vilimas Gintalas Surveyor, Road designer, Telšiai, Lithuania



curvature change rate of road alignment, geometric road design, horizontal curves, road safety, road safety criteria, road safety module


The studies in various countries show that one of the main causes of accidents on rural roads still remains the drivers’ errors in choosing safe speed, which can be attributed to the errors of perceiving the road alignment. The current practice shows that the engineering safety improvement measures as well as accident prevention measures such as intersection design, traffic signs and equipment, facilities for vulnerable road users, access management, and human behaviour are not always effective. Probably, one of the alternatives to solve this problem is a design methodology that is used in the European Union countries and based on road safety criteria and road safety module. This methodology is aimed at ensuring design consistency between the elements of road alignment in a way that the driver intuitively chooses safe speed or the probability of errors in perceiving the road alignment is minimum. The article presents experimental research carried out in Vilnius Gediminas Technical University, the objective of which is to determine the accuracy of road safety module and to suggest possible alternatives for its improvement.


AASHTO. (2018). A policy on geometric design of highways and streets. American Association of State Highway Officials. The Green Book (7th ed.), Washington, D. C.

Al-Sahili, K., & Dwaikat, M. (2019). Modeling geometric design consistency and road safety for two-lane rural highways in the West Bank, Palestine. Arabian Journal for Science and Engineering, 44, 4895–4909.

Bauer, K.M., & Harwood, D.W. (2013). Safety effects of horizontal curve and grade combinations on rural two-lane highways. Transportation Research Board, 2398(1), 37–49.

Bogenreif, C., Souleyrette, R.R., & Hans, Z. (2012). Identifying and measuring horizontal curves and related effects on highway safety. Journal of Transportation Safety & Security, 4(3), 179–192.

Bosurgi, G., & D’Andrea, A. (2012). A polynomial parametric curve (PPC-CURVE) for the design of horizontal geometry of highways. Computer-Aided Civil and Infrastructure Engineering, 27(4), 304–a312.

Camacho-Torregrosa, F.J., Pérez-Zuriaga, A.M., Campoy-Ungría, J.M., & García, A. (2015). Use of heading direction for recreating the horizontal alignment of an existing road. Computer-Aided Civil and Infrastructure Engineering, 30(4), 282–299.

Colonna, P., Intini, P., & Berloco, N. (2018). Integrated American-European protocol for safety interventions on existing two-lane rural roads. European Transport Research Review, 10, Article 5.

Colonna, P., Berloco, N., Perruccio, P. I. A., & Ranieri, V. (2016). Evaluating the skidding risk of a road layout for all types of vehicle. Transportation Research Record: Journal of the Transportation Research Board, 2591(1), 94–102.

Easa, S. M., & Mehmood, A. (2008). Optimizing design of highway horizontal alignments: New substantive safety approach. Computer-Aided Civil and Infrastructure Engineering, 23(7), 560–573.

Elvik, R. (2019). The more (sharp) curves, the lower the risk. Accident Analysis & Prevention, 133, Article 105322. Forschungsgesellschaft für Straßen- und Verkehrswesen. (2012). Richtlinien für die Anlage von Landstraßen (RAL). Köln.

Gemechu, S. M., & Tulu, G. S. (2021). Safety effects of geometric design consistency on two-lane rural highways. The case of Ethiopia. American Journal of Traffic and Transportation Engineering, 6(4), 107–115.

Gintalas, V. 2010. Possibilities for the improvement of the quality of design solutions in the gravel road reconstruction projects. The Baltic Journal of Road and Bridge Engineering, 5(3), 177–184.

Intini, P., Berloco, N., Ranieri, V., & Colonna, P. (2020). Geometric and operational features of horizontal curves with specific regard to skidding proneness. Infrastructures, 5(1), Article 3.

Khan, G., Bill, A.R., Chitturi, M., & Noyce, D.A. (2012). Horizontal curves, signs, and safety. Transportation Research Board, 2279(1), 124–131.

Lamm, R., Beck, A., Rusher, T., & Mailaender, T. (2007). How to make two-lane rural roads safer. Scientific background and guide for practical application. WIT Press.

Lamm, R., Psarianos B., Soilemezoglou G., & Kanellaidis, G. (1996). Driving dynamic aspects and related safety issues for modern geometric design of non-built-up roads. Transportation Research Record, 1523(1), 34–45.

Lamm, R., Psarianos, B., Kontaratos, M., Drymalitou, D., & Soilemezoglou, G. (1995). Guidelines for the design of highway facilities. Volume 3: Alignment. Ministry for Environment, Regional Planning and Public Works, Athens, Greece.

Lamm, R., Mailaender, T., & Pasarianos, B. (1999). Highway design and traffic safety engineering handbook. MCGraw-Hill.

Montella, A., & Imbriani, L.L. (2015). Safety performance functions incorporating design consistency variables. Accident Analysis and Prevention, 74, 133–144.

Peltola, H., Rajamäki, R., & Luoma, J. (2012). Tools needed for enhancing transferability of cost-effective road safety measures. Procedia – Social and Behavior Sciences, 48, 1234–1243.

Shao, Y., Xu, J., Li, B., & Yang, K. (2014). Modeling the speed choice behaviors of drivers on mountainous roads with complicated shapes. Advances in Mechanical Engineering, 7(2), Article 862610.

Swedish National Road Administration. (1986). Standard specifications for geometric design of rural roads. Borlaenge.

Swiss Association of Road Specialists. (1991). Highway design, fundamentals, speed as a design element. Zurich.

Trafikverket. (2015). TRVK Krav utformning av vägar och gator. www.

Oña, J., Garach, L., Calvo, F., & García-Muñoz, T. (2014). Relationship between predicted speed reduction on horizontal curves and safety on two-lane rural roads in Spain. Journal of Transportation Engineering, 140(3), Article 04013015.




How to Cite

Bertulienė, L., Girdvainis, R., Juknevičiūtė-Žilinskienė, L., & Gintalas, V. (2024). Improvement of Curvature Change Rate (Parameter) in Two-Line Rural Roads. The Baltic Journal of Road and Bridge Engineering, 19(1), 34-52.