M22-01. 20 Design Manual
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- 1360.03(5) Two-Way Ramps
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Ramp Width (ft) Traveled Way [1] 11-13 [5] 23-25 [3] [5] Shoulders Right 4-8 [2] [5] 4-8 [2] [5] Left 2 2-4 Medians [4] 6 6-8 Notes: [1] Evaluate shoulder use to accommodate offtracking, if determined inadequate for operational performance needs, apply turning roadway widths in Chapter 1240. [2] Provide width necessary to accommodate offtracking by large vehicles. [3] Add 12 ft for each additional lane. [4] The minimum two-way ramp median width (including shoulders) is given. Wider medians may be required for signs or other traffic control devices and their respective clearances. When either the on- or off-ramp is single-lane, use the one-lane column. If both directions are two lanes, use the two-lane column. [5] Use the mode/function/performance approach described in Chapter 1106 to choose between the range of widths given. Ramp shoulders may be used by large trucks for offtracking and by smaller vehicles cutting to the inside of curves. Evaluate the need to pave shoulders full depth for larger vehicle offtracking using turn simulation software on one-way ramps to accommodate this type of use. If operational performance needs demonstrate that accommodation of offtracking on shoulders is inadequate apply turning roadway widths in Chapter 1240. 1360.03(5) Two-Way Ramps Two-way ramps are on- and off-ramps on a single roadway. Design two-way ramps as separate one-way ramps. Provide a raised median to physically separate the on- and off- ramps. Wider medians than given in Exhibit 1330-6 may be required for signing or other traffic control devices and their clearances. (For signs, it is sign width plus 4 feet.) Where wider medians are required, provide a 2-foot clearance between the face of curb and the edge of traveled way. Where additional width is not required, the raised median width may be reduced to a double-faced mountable or extruded curb. Traffic barrier or a depressed median may be provided in place of the raised median. |