Effect of Geometric Factors on Lateral Position of Vehicles in Freeway Buffer-Separated Managed Lanes

Abstract

Chapter 3 in the 2004 AASHTO high-occupancy-vehicle guidelines includes a prioritized trade-off table of various design options for high-occupancy-vehicle lanes (now known as managed lanes). The design trade-offs include the reduction of lane, shoulder, or buffer width. The key measure thought to be affected by lane, shoulder, and buffer width is lateral position. The presented study identified the relationship between operations and cross-section width, including the type of buffer design separating the managed lanes from the general-purpose lanes. This research study collected lateral position data on existing managed lane facilities with a range of geometric elements within both tangent and horizontal curves and identified potential relationships between the geometric design element values and the measure of effectiveness. The field studies included data collected at 28 sites with fixed video cameras and along 161 centerline miles with an instrumented vehicle that recorded data for the vehicle immediately in front of the instrumented vehicle. The study found that managed-lane drivers shifted away from the pylons placed in the buffer. Horizontal alignment (tangent or curve) and the direction of the horizontal curve (left or right) influenced lateral position. Left shoulder, lane, and buffer width affected lateral position. Modifying a 6.5-ft shoulder to a minimum shoulder (i.e., 1.5 ft) will result in drivers moving to the right about 0.5 ft; however, if an 18.5-ft shoulder is reduced by 5 ft, the impact in operations is negligible (drivers would shift only about 0.11 ft toward the right).

Imaging Analysis of Prosthesis Angle after Hip Replacement with Direct Anterior Approach in Lateral Position

“…The DAA does not damage the muscles around the hip joint, does not cause significant damage to the posterior structures of the hip capsule, and has a better postoperative balance of lower limb muscle strength than the traditional approach, so it has the accuracy of prosthesis placement and good postoperative hip stability, reducing the risk of postoperative soft tissue imbalance caused by periprosthetic muscle injury and postoperative hip dislocation caused by improper placement of the prosthesis [ 22 ]. Daily activities such as squatting, sitting on a low stool, and bending to put on socks and laces can be performed in the early postoperative period, and no special protection is needed for the postoperative hip joint [ 23 – 25 ]. In this paper, we used imaging to observe the angle of the posterior prosthesis and showed that hip arthroplasty using the direct anterior approach improved hip mobility in early stages compared with other approaches and reduced pain.…”

Estimating lateral placement and lane indiscipline of urban mixed traffic of a developing country: an ANN-assisted approach

“…Among road geometric factors, influences of lane width and shoulder width on LP of vehicles were examined. It was thoroughly reported in literature (Lindheimer et al 2017;Mecheri et al 2017) that vehicles are shifting away from the edge of carriageway as lane width increases. On the other hand, with the increase in shoulder width, vehicles shift laterally towards the edge of carriageway (Van Driel et al 2004;Mecheri et al 2017;Lindheimer et al 2017).…”

“…It was thoroughly reported in literature (Lindheimer et al 2017;Mecheri et al 2017) that vehicles are shifting away from the edge of carriageway as lane width increases. On the other hand, with the increase in shoulder width, vehicles shift laterally towards the edge of carriageway (Van Driel et al 2004;Mecheri et al 2017;Lindheimer et al 2017). Also, treatments like installation of rumble strips, have impacts on lateral placement of vehicles (Porter et al 2004;Gates et al 2012).…”

“…Dey et al (2006) and Balaji et al (2013) pasted cloth tapes on the pavement to divide the carriageway width into a number of segments having equal widths during field data collection via videography. Lindheimer et al (2017) drew few parallel lines on a transparent sheet. The sheet was kept on the computer screen in such a manner so that the parallel lines could divide the carriageway width into a given number of segments when the video of traffic D r a f t movements was played on the computer.…”

“…The sheet was kept on the computer screen in such a manner so that the parallel lines could divide the carriageway width into a given number of segments when the video of traffic D r a f t movements was played on the computer. Few studies (Mahapatra and Maurya 2015;Balaji et al 2013;Dey et al 2006;Lindheimer et al 2017) witnessed LP of vehicle may vary with the category of subject vehicle. It was observed that fast moving vehicles prefer to move on median lane rather than shoulder lane.…”