What Does Edge Of Pavement (EP) Mean In Construction?
What Does Edge Of Pavement (EP) Mean In Construction?
Edge of pavement (EP) is a designation used on site plans to clearly indicate the areas that are the interface of one material and the adjacent pavement surface. This designation is used to identify the extent of the pavement, whether it is concrete, asphalt, gravel or landscaping.
EP can also be used to refer to the area adjoining the outer edge of the roadway, which includes the entire area within the right of way.
The EP designation is often used in conjunction with other terms such as falsework (temporary construction used to support structural elements), profile grade (elevation or gradient of a trace plane usually intersecting the top surface of the proposed wearing surface), and roadway prism (the portion of a highway within limits of construction).
These terms are all related to road and bridge construction and are important for understanding how roads are built.
What Is The Purpose Of The Edge Of Pavement (Ep)?
The purpose of an Edge of Pavement (EP) designation is to clearly indicate the areas that are the interface between one material and the adjacent pavement surface.
This designation is used on site plans to identify the extent of the pavement, and it is typically accompanied by a change in slope at this line between the two materials.
Edge line markings may be used where edge delineation is desirable to minimize unnecessary driving on paved shoulders or on refuge areas that have lesser structural pavement strength than the traveled way.
Raised pavement markers should not supplement right-hand edge lines unless an engineering study or engineering judgment indicates that providing them is likely to increase safety.
Edge line markings may also be excluded based on engineering judgment, for reasons such as if the traveled way edges are delineated by curbs, parking, or other markings.
How To Designate An EP?
Edge of pavement (EP) is a designation used on site plans to clearly indicate the areas that are the interface of one material and the adjacent pavement surface.
Edge treatment for hot mix asphalt pavement typically consists of a safety edge with a sloped edge of 30 degrees placed at the edge of roadway pavement.
For concrete pavement, edge treatments must comply with Section 40, “Concrete Pavement,” of the Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges.
Edge line pavement markings delineate the right or left edges of a roadway and are typically solid yellow lines for left edges and solid white lines for right edges.
Raised pavement markers should not supplement right-hand edge lines unless an engineering study or engineering judgment indicates the need to do so.
The NCDOT Pavement Design Procedure AASHTO 1993 Method recommends minimum depths for pavement designs based on the effective modulus of the pavement layer (Ep).
The FDOT Pavement Marking Program provides tools within Design & Computation to draw pavement markings such as edge lines and crosswalk markings.
How To Measure The Edge Of Pavement (Ep)?
Measuring the edge of pavement (EP) involves determining the angle from the plane of the adjacent finished pavement surface. This is typically done with a steel ruler or measuring tape.
The angle should be measured at various points, such as within 200 feet of the start of paving, at the start/end of a curve’s superelevation, and between adjoining pavements.
The Federal Highway Administration (FHWA) recommends that safety edge angles should be between 8-12 degrees for asphalt pavements and 6-10 degrees for concrete pavements. The FHWA also provides guidance on how to measure these angles in the field using Figure 670-3.
Additionally, there are Standard Special Provisions for asphalt and concrete that provide examples of typical cross sections and quantities for edge treatments.
According to research conducted by the University of Michigan, measurements of pavement markings at railroad crossings can also be used to determine longitudinal pavement profiles.
In some cases, the International Roughness Index (IRI) of a single track on one side of a lane can be used as an indicator for overall pavement profile quality.
