An Analysis of Sight Distances Considering Both the Vertical and Horizontal Curves of a Tourist Bound Destination Highway in Camarines Sur: The Lagonoy-Presentacion Section

Document Type : Regular Article


Professor, College of Engineering and Technology, Partido State University, Goa, Camarines Sur, Philippines


This analyzed sight distances contemplating both vertical and horizontal curves of a tourist bound destination highway in Camarines Sur, particularly the Lagonoy to Presentacion section. The Quantum Geographic Information System (QGIS) was used. The data were validated through site observation. The radius, tangent and sight distances for horizontal curves were obtained through graphical measurement while the elevations, length, slopes of both forward and back tangents, and sight distances of vertical curves were computed using mathematics formula. The decision sight distance and the equivalent maximum speed values were deduced through the policies imposed by the American Association of State Highway and Transportation Officials (AASHTO [1]). The highway has numerous horizontal and vertical curves with radius, tangent distances, intersecting angles, curve lengths; elevations of point of curvature (PC), point of tangencies (PT), and point of intersections (PI); and slope of forward and back tangent causal to short sight distances, delimiting car speeds. Through the obtained sight distance data, the maximum speed limit map was completed.


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[1]     A Policy on geometric design of highways and streets. 2001.
[2]     Hassan Y, Easa SM. Sight distance red zones on combined horizontal and sag vertical curves. Can J Civ Eng 1998;25:621–30. doi:10.1139/l97-127.
[3]     Hassan Y, Sayed T. Effect of driver and road characteristics on required preview sight distance. Can J Civ Eng 2002;29:276–88. doi:10.1139/l02-002.
[4]     Abbas SKS, Adnan MA, Endut IR. An Investigation of the 85th Percentile Operating Speed Models on Horizontal and Vertical Alignments for TwoLane Rural Highways: A Case Study. J - Inst Eng Malaysia 2012;73:31–40.
[5]     Goktepe A, Lav A, Altun S. Dynamic Optimization Algorithm for Vertical Alignment of Highways. Math Comput Appl 2005;10:341–50. doi:10.3390/mca10030341.
[6]     S.A. Shebl. Single reverse and unsymmetrical vertical curve for highways utilizing quintic polynomial equation of odd powers. J Comput Appl Math 2015;4:1–7. doi:10.4172/2168-9679.1000257.
[7]     Chen T, Zhang M, Wei L. Driver Behavior on Combination of Vertical and Horizontal Curves of Mountainous Freeways. Math Probl Eng 2014;2014:1–9. doi:10.1155/2014/432841.
[8]     Bassan S. Sight distance restriction on highways’ horizontal curves: insights and sensitivity analysis. Eur Transp Res Rev 2016;8:21. doi:10.1007/s12544-016-0208-6.
[9]     Castro M, Iglesias L, Sánchez JA, Ambrosio L. Sight distance analysis of highways using GIS tools. Transp Res Part C Emerg Technol 2011;19:997–1005. doi:10.1016/j.trc.2011.05.012.
[10]    P. Discett. Analysis on desired speed and traffic sign sight distance. Mod Traffic Transp Eng Res 2014:48–53.
[11]    Al-Kaisy A, Krieder T, Pothering R. Speed selection at sites with restrictive alignment: the US-191 case study. Adv Transp Stud 2013;29:71–82.
[12]    Fink KL, Krammes RA. Tangent length and sight distance effects on accident rates at horizontal curves on rural two-lane highways. Transp Res Rec 1995:162–8.
[13]    Ali MZA, Easa SM, Hamed M. Stop-Controlled Intersection Sight Distance: Minor Road on Tangent of Horizontal Curve. J Transp Eng 2009;135:650–7. doi:10.1061/(ASCE)0733-947X(2009)135:9(650).
[14]    Easa SM. Design considerations for highway reverse curves. Transp Res Rec 1994:1–11.
[15]    Matsoukis E. A parsimonious model for the safety assessment of horizontal curves using data from rural roads. WIT Press; 2011. doi:10.2495/SAFE110041.
[16]    Jalal Kamali MH, Monajjem MS, Ayubirad MS. Studying the effect of spiral curves and intersection angle, on the accident ratios in two-lane rural highways in Iran. PROMET - Traffic&Transportation 2013;25. doi:10.7307/ptt.v25i4.332.
[17]    Easa SM, Hassan Y. Development of transitioned vertical curve II Sight distance. Transp Res Part A Policy Pract 2000;34:565–84. doi:10.1016/S0965-8564(99)00037-3.
[18]    Zhang Y. Analysis of the Relation between Highway Horizontal Curve and Traffic Safety. 2009 Int. Conf. Meas. Technol. Mechatronics Autom., IEEE; 2009, p. 479–81. doi:10.1109/ICMTMA.2009.511.
[19]    Dabbour E. Optimizing Highway Profiles for Individual Cost Items. Int J Traffic Transp Eng 2013;3:440–7.
[20]    Sun J, Chen C. Length requirements for new single-arc unsymmetrical crest vertical curve for highways. Adv Mater Res 2015;1065:755–9.
[21]    de Oña J, Garach L, Calvo F, García-Muñoz T. Relationship between Predicted Speed Reduction on Horizontal Curves and Safety on Two-Lane Rural Roads in Spain. J Transp Eng 2014;140:04013015. doi:10.1061/(ASCE)TE.1943-5436.0000624.
[22]    Luque R, Castro M. Highway Geometric Design Consistency: Speed Models and Local or Global Assessment. Int J Civ Eng 2016;14:347–55. doi:10.1007/s40999-016-0025-2.
[23]    Harwood DW, Bauer KM. Effect of Stopping Sight Distance on Crashes at Crest Vertical Curves on Rural Two-Lane Highways. Transp Res Rec J Transp Res Board 2015;2486:45–53. doi:10.3141/2486-06.