The Evaluation of Friction Demand Factor in Loop Ramps of Interchange Facilities

Document Type : Research Article

Authors

Department of Transportation Engineering, Isfahan University of Technology, Isfahan, Iran

Abstract

The aim of this study is to evaluate the side friction demand factor in the loop ramps of interchange facilities. The substantial exclusivity of these ramps is the existence of horizontal curves, combined with longitudinal grades. In this study, CarSim and TruckSim software packages, as simulation tools, are applied. Both passenger cars and heavy vehicles are used. The vehicles used in simulations were Hatchback and Sedan (as passenger cars) and Truck (as heavy vehicle). In addition, two various types of loop ramps, including Curve-Curve-Curve and Spiral-Curve-Spiral, in two different conditions (braking and no-braking) are examined. The results showed that the side friction demand factor values assumed by AASHTO Green book (as a main geometric design guideline) are uncertain. In the condition of no-braking, the differences between AASHTO values and the simulation results for uphill and downhill states are 24% and 18%, respectively. In braking condition, similar differences for uphill and downhill are 124% and 135%, respectively. Additionally, based on the regression analysis of the simulation results, the appropriate side friction demand factor models were achieved for different conditions. The findings of the study verify the necessity of revising the friction demand values, especially for the design of interchange loop ramps.

Keywords

Main Subjects


[1] S. Najafi, G.W. Flintsch, A. Medina, Linking roadway crashes and tire–pavement friction: a case study, International Journal of Pavement Engineering, 18(2) (2017) 119-127.
[2] A. Mehrara Molan, A. Abdi Kordani, Multi-Body Simulation Modeling of Vehicle Skidding and Roll over for Horizontal Curves on Longitudinal Grades, in: Transportation Research Board 93rd Annual Meeting, 2014.
[3] A.A. Kordani, A.M. Molan, The effect of combined horizontal curve and longitudinal grade on side friction factors, KSCE Journal of Civil Engineering, 19(1) (2015) 303-310.
[4] A.A.o.S. Highway, T. Officials, A Policy on Geometric Design of Highways and Streets, 2011, Aashto, 2011.
[5] S.M. Easa, E. Dabbour, Design radius requirements for simple horizontal curves on three-dimensional alignments, Canadian Journal of Civil Engineering, 30(6) (2003) 1022-1033.
[6] E. Donnell, J. Wood, S. Himes, D. Torbic, Use of Side Friction in Horizontal Curve Design: A Margin of Safety Assessment, Transportation Research Record: Journal of the Transportation Research Board, (2588) (2016) 61-70.
[7] T. Varunjikar, Design of horizontal curves with downgrades using low-order vehicle dynamics models, The Pennsylvania State University, 2011.
[8] S. Mavromatis, B. Psarianos, P. Tsekos, G. Kleioutis, E. Katsanos, Investigation of vehicle motion on sharp horizontal curves combined with steep longitudinal grades, Transportation Letters, 8(4) (2016) 220-228.
[9] T.-H. Chang, Effect of vehicles’ suspension on highway horizontal curve design, Journal of transportation engineering, 127(1) (2001) 89-91.
[10] D. Torbic, M. O’Laughlin, D. Harwood, K. Bauer, C. Bokenkroger, L. Lucas, J. Ronchetto, S. Brennan, E. Donnell, A. Brown, NCHRP Report 774: Superelevation Criteria for Sharp Horizontal Curves on Steep Grades, Transportation Research Board of the National Academies, Washington, DC, (2014).
[11] D. Torbic, E. Donnell, S. Brennan, A. Brown, M. O’Laughlin, K. Bauer, Superelevation design for sharp horizontal curves on steep grades, Transportation Research Record: Journal of the Transportation Research Board, (2436) (2014) 81-91.
[12] F. Awadallah, Theoretical analysis for horizontal curves based on actual discomfort speed, Journal of transportation engineering, 131(11) (2005) 843-850.
[13] J. Hall, K. Smith, L. Titus-Glover, J. Wambold, T. Yager, Z. Rado, Guide for pavement friction. NCHRP. Web-only document 108. Contractor’s inal Report NCHRP Project 01-43, Transportation Research Board of the National Academes, (2009).
[14] J. Morrall, R. Talarico, Side friction demanded and margins of safety on horizontal curves, Transportation Research Record, 1435 (1994) 145.
[15] http://www.carsim.com, Mechanical Simulation Corporation, in, 2017.
[16] G. Furtado, S. Easa, A. Abd El Halim, Vehicle stability on combined horizontal and vertical alignments, National Library of Canada= Bibliothèque nationale du Canada, 2003.
[17] M.W. Sayers, Vehicle dynamics programs for roadway and roadside studies, UMTRI-98-20-1, Transportation Research Institute, University of Michigan, 1999.
[18] A.A. Kordani, A.M. Molan, S. Monajjem, New Formulas of Side Friction Factor Based on Three-Dimensional Model in Horizontal Curves for Various Vehicles, in: T&DI Congress 2014: Planes, Trains, and Automobiles, 2014, pp. 592-601.
[19] A.A. Kordani, M.H. Sabbaghian, B. Tavassoli Kallebasti, Analyzing the influence of Coinciding Horizontal Curves and Vertical Sag Curves on Side Friction Factor and Lateral Acceleration Using Simulation Modeling, TRR Journal, (2015).
[20] J. Bonneson, NCHRP Report 439: Superelevation Distribution Methods and Transition Designs, Transportation Research Board, National Research Council, Washington, DC, (2000).
[21] J.A. Bonneson, Side friction and speed as controls for horizontal curve design, Journal of Transportation engineering, 125(6) (1999) 473-480.
[22] S. Easa, A. El Halim, Radius requirements for trucks on three-dimensional reverse horizontal curves with intermediate tangents, Transportation Research Record: Journal of the Transportation Research Board, (1961) (2006) 83-93.
[23] J. Gattis, B. Finley Vinson III, L.K. Duncan, Low-speed horizontal curve friction factors, Journal of transportation engineering, 131(2) (2005) 112-119.
[24] S. Mavromatis, E. Papadimitriou, B. Psarianos, G. Yannis, Vehicle Skidding Assessment through Maximum-Attainable Constant-Speed Investigation, Journal of Transportation Engineering, Part A: Systems, 143(9) (2017) 04017044.
[25] H.F. Mollashahi, K. Khajavi, A.K. Ghaeini, Safety Evaluation and Adjustment of Superelevation Design Guides for Horizontal Curves Based on Reliability Analysis, Journal of Transportation Engineering, Part A: Systems, 143(6) (2017) 04017013.
[26] K. You, L. Sun, Reliability analysis of vehicle stability on combined horizontal and vertical alignments: Driving safety perspective, Journal of Transportation Engineering, 139(8) (2013) 804-813.