How to Read Highway Blueprints
Civil engineers design highways and create large sets of documents called highway blueprints. These plans are sheets of drawings and charts that illustrate proposed new roadways or existing road improvements. Highway blueprints convey design, construction and right-of-way information that designers, contractors, estimators, construction workers, appraisers, negotiators, attorneys and property owners use.
Contact your Department of Transportation to obtain a copy of its design manual for current design standards, symbols, abbreviations and plan preparation techniques to refer to while reviewing the highway blueprints you have in mind. Obtain a Right-of-Way Plan Manual, if applicable, for standards and technique reference as well.
Look at the cover, or title sheet, which is the first sheet in the set of highway blueprints. Cover sheet information includes the project name, number, identification number, standard specification reference, date of plan completion, signatures of the person responsible for plan design and the professional engineer’s stamp.
Look for the project location sketch and layout view. The project location sketch shows the general geographic area and limits of the project, and the layout view shows the beginning and ending stations of the project. Look over any design data, indicating traffic data, number of lanes and depth of paving.
Look over the revision summary sheet, which lists any revisions made after the final set of plans were completed and issued. This records the revision date, plan sheet number and a brief description of changes.
Review the index sheet. Larger projects usually have a separate index sheet, while smaller projects include this on the cover. The index sheet lists any sheet additions or deletions and the total number of sheets.
Look at each sheet in the set. Each will have a box containing project information such as project name and number, sheet number and total number of sheets. Each sheet has a north arrow and scale. The scale corresponds to the plans and details on each sheet. Measure using an engineer’s scale, which is a measuring device similar to a ruler but equates 1 inch to multiples of tens or hundreds, such as 1 inch equals 100 feet.
Look through the construction sheets. These include general notes, schematic plans, sections, summary of quantities, detailed estimates, traffic assignments, roadway plans, interchange plans, ramp or side street profiles, driveway profiles and drainage maps. Some plans also include staging and detour plans, utility plans, signing and marking plans, sound barrier plans, erosion and sediment control plans, borrow pit location and notes, special design culverts, retaining wall plans and bridge plans.
Look through the right-of-way sheets. These sheets include a centerline plat, a property map, a summary of additional right-of-way sheets and detailed right-of-way plans. Some sets include a separate title sheet, utility plan sheet and schematic plan sheet.
- Most construction drawings orient true north at the top of the sheet; however, highway plans are usually large and span multiple sheets. The accepted practice is to extend the plans from left to right regardless of the north direction.
- Check to see that every sheet bears the signature of a licensed design professional, usually the state highway engineer. This indicates that the information on the sheet was prepared and approved with that person’s authority.
Teresa B. Cross is a professional architect based in Southern California. She holds a Bachelor of Science in architecture from the University of Virgina and a Master of Studies in interdisciplinary design for the built environment from the University of Cambridge. Cross also received LEED accreditation from the U.S. Green Building Council in 2010.
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