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Morgan State University Chavis · Fall 2017

Lab 1 - Design of Alignments Due Thursday, October 6

Problem Statement

Morgan State University has hired you to prepare a report regarding the safety along Hillen Ave./Perring Pkwy due to the geometric alignment. It has come to the University’s attention that a high number of accidents have occurred along the corridor. For a map of crashes see https://c-chavis.carto. com/viz/7aa334f0-5d7c-11e6-a973-0e05a8b3e3d7/public_map

Specifically the University has two areas of concern (see Figure 1 ):

1

2

Figure 1: Study site locations

1. The horizontal curve just north of E. Cold Spring Lane.

2. The vertical curve between E. Cold Spring Lane and Argonne Rd.

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Morgan State University Chavis · Fall 2017

Report Guidelines

Your report needs to include the following:

• A clear introduction

• The vertical and horizontal (1) alignments drawn to scale at whole station intervals. If drawing by hand, please use graphing paper. For the vertical alignment a table of the elevations at each station must be provided. For horizontal alignment a table with the deflection (feet) angle (degrees) and chord lengths (feet) must be provided. Also, it must be clearly shown how the deflection angle and chord length was used to construct the horizontal alignment. Be sure to include the scale on your diagrams.

• An analysis determining if the each of the problem areas is safe from a geometric design point of view. You need to determine if the length of the curve is sufficient and if there are any horizontal sight obstructions. Test if the curve is safe at the speed limit of 35 mph and at 40 mph.

• Solutions addressing any problems you find during the analysis.

In the report please refer in units of feet and stations. Report all calculations and provide the values used for the horizontal and vertical alignments at every whole station between the beginning and end of the curve.

Be sure to write assumptions, results and conclusions. Each group is also expected to complete a report presented in a professional format that is consistent with one specific style manual (Chicago, APA, etc.). Be sure to make consistent use of font type, font size, margins, justification, line spacing, page number, headings, etc. as you complete your work. Display your findings in a sequential and logical manner, and when needed, through the use of appropriate tables, graphs, or other methods of presenting quantitative or qualitative data.

You may work in groups of two.

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Morgan State University Chavis · Fall 2017

Tips

Vertical Alignment

In order to determine the alignment of the crest curves the beginning and ending grades must be determined as well as the length of the curve. This will require the use of software to determine the elevation. Two options are to use Google Earth Software or the MapMyRun route creation tool (http://www.mapmyrun.com/routes/create/). I suggest the latter as its easier to map the route.

You need to calculate and clearly label the grades (G1, G2) of each tangent, station and elevation of the PVC, PVI, and PVT, the length of the curve (L). Determine the station and elevation of the highest point. You may assume that the PVC occurs at Station 0 for simplicity if you like.

Horizontal Alignment

Assume the given curve is a simple curve. In order to lay out the horizontal alignment you need to first determine the intersection angle, ∆, and then the length of the curve. A print out of the map at that location, a ruler and protractor will aid you in determining those values.

Other

Using standards and equations presented in lecture, calculate SSD, minimum curve length, and other parameters to evaluate the existing plan. If you found evidence that the standards are not met, provide practical solutions to improve safety.

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