Section 3: Schematic Layouts

Schematic layouts should include the basic information necessary for a proper review and evaluation of the proposed improvement. The following should be included at a minimum and the adequacy verified with each submission of a schematic:

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  • A Design Summary Report (DSR) appropriate for the stage of the project development
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  • General project information, including TxDOT District, County, Control-Section-Job (CSJ), roadway name, project limits, project length, stationing equations, project location map, design speed, functional classification, and existing and projected ADT volumes
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  • TxDOT logo and copyright, the Engineer's firm name (if applicable), the Preliminary Engineer's Seal, the percent complete, and the date of latest revision
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  • North arrow, legend, drawing scales, and labeling for the beginning and ending of the project
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  • Traffic diagram(s) showing existing and projected ADT volumes of main lanes, ramps, frontage roads, turnarounds, and cross roads, and the breakdown of those volumes for turning movements, as applicable
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  • Proposed horizontal and vertical alignments for proposed main lanes, ramps, frontage roads, ancillary roads, and cross roads, including labels for all curve data, elevations, grades, and minimum vertical clearances over highways Superelevation rates, locations, and transition lengths
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  • Existing and proposed bicycle and pedestrian accommodations, including curb ramp locations and roadway crossing locations
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  • Existing and proposed horizontal alignments for railroads
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  • Existing roadways in plan-view and existing ground profiles and elevations along each proposed alignment
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  • Existing vertical alignments for cross roads to remain in place at proposed interchanges or grade separations
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  • Pavement marking and arrows indicating the number of lanes, direction of travel, and lengths of lane/shoulder tapers and weaving areas
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  • Aerial imagery or an orthophotograph in the plan view, if available
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  • Locations and widths of medians and median openings
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  • Lengths and geometrics of speed change lanes, turn lanes, auxiliary lanes, and storage bays
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  • Portions of existing roadways and structures to be removed or closed
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  • Existing and proposed right of way (ROW) limits, property lines, and driveways
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  • Existing and proposed control-of-access (COA) lines
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  • Relevant affected utilities
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  • Existing and proposed bridges and bridge class culverts, including the beginning and ending stations of each proposed structure
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  • Locations of retaining walls and/or noise walls
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  • Existing and proposed typical sections for main lanes, ramps, frontage roads, ancillary roads, and cross roads, including the following elements:
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  • If the proposed design is interim, include typical sections for the ultimate design with the above parameters indicated
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  • Locations of wildlife crossing structures
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  • Vertical location of cross-drainage structures in the profile view
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  • Rivers, major stream crossings, and FEMA floodplain areas reflect the anticipated water surface for the required design event
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  • Locations and composition of existing and proposed freeway signing
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  • A written explanation or prepared exhibits of the sequence and methods of staged construction, including the treatment of crossovers and ramps

Each schematic should be able to stand alone, even if part of a larger project. The proposed roadway should tie into the existing roadway as it will be at the time of construction. Any adjacent projects (concurrent or future) should be shown and labeled as “By Others”, “Future” or similar.

For freeway added capacity and interchange/ramp modification projects, and major highway and intersection reconstruction projects, traffic operational and safety analyses are recommended. The traffic operational analysis is based on the Highway Capacity Manual (HCM) or microsimulation tools. The safety analyses include a historical crash data analysis for at least four years and Crash Modification Factors (CMF) and/or crash prediction models as detailed in the Highway Safety Manual (HSM). For guidance on the scope of operational and safety analyses and applicable tools, contact the Design Division.

A comprehensive checklist for schematics, covering the above elements as well as other documentation requirements and considerations, can be found on the Design Division - Plan Development Support Section website.

All schematics are to be submitted to the Design Division for review. The Design Division will provide approvals for schematics on the NHS and Interstate, as well as Major Projects and any other project identified on the FHWA's Projects of Division Interest (PoDI) list. If a project is on the PoDI and the project's PoDI Risk Analysis Stewardship & Oversight Plan (PoDI Plan) identifies that the project's schematic is to be reviewed by the FHWA, the Design Division will submit the schematic to the FHWA for review. For all other schematics, approvals will be at the District.

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