4.4.1 Roadway

4.4.1.1 Typical Section Optimization
Typical sections are optimized to reflect any changes to the recommended alternative and incorporate results of the Safer by Design tool (see
Section 4.4.1.3
).
Once the recommended alternative is selected, typical sections are optimized to ensure that all design criteria is met and all desired elements are incorporated into the typical section including multimodal accommodations, clear zone, border width, utility strip, etc. Typical sections must meet the design criteria specified in the RDM and
must be developed for all roadway components
 including mainlanes, frontage roads, ramps, turnarounds and cross streets.
Evaluate the typical sections in accordance with the RDM’s Performance Based Practical Design methodology.
4.4.1.2 Horizontal and Vertical Alignment Refinement
Horizontal and vertical alignments are fully designed once a recommended alternative is selected. Horizontal/vertical alignments are designed for
all roadway components
 including mainlanes, frontage roads, ramps, turnarounds and cross streets. All alignments must meet the design criteria specified in the RDM.
Considerations in horizontal/vertical alignment design include:
  • Ensure vertical clearances are met for bridge structures including bridges over turnarounds – determine if route is on the Texas Highway Freight Network (THFN (Statewide Planning Map);
  • Determine if the route is part of a hurricane evacuation route (Statewide Planning Map);
  • Avoid changes to ROW limits and locations of ramps shown on the schematic after DES approval review or FHWA Federal action interstate access approval; and
  • Consider underground features, such as utilities, storm sewer systems and septic tank systems, when making alignment adjustments.
Changes to the horizontal and vertical alignments after a public meeting or hearing may require TxDOT to repeat the review and approval process for the environmental document and hold additional meetings/hearings. Minor adjustments to alignments may be made by the designer if the change is feasible and does not compromise project design criteria.
Substantial changes to an approved geometric schematic will require submission of the revised schematic to DES.
Coordinate any changes to the design with the District Environmental Coordinator to ensure that environmental studies and documents are appropriately updated. Some changes may warrant revisions to previously completed environmental studies. See
Chapter 5
for more information regarding the coordination of design and environmental tasks.
4.4.1.3 Safer by Design Tools
TxDOT developed the Safer by Design tools (formerly the Safety Scoring Tools) that are used to assist designers in evaluating potential safety enhancements during project development and design.
The Safer by Design Tools incorporate quantified effects of changes in design parameters such as lane and shoulder width, horizontal and vertical curve geometry, rumble strips and clearances to objects, thereby allowing designers to examine the effects and tradeoffs involved in design decisions.
The Safer by Design tools should be used prior to obtaining any additional survey and/or SUE to ensure that ROW that may be needed for the optimized design is identified. Districts are required to document the initial and final safety score, for applicable projects, on the Form 1002, which are required with interim and final PS&E submissions.
The tool is not designed or intended to make decisions for the designer, but rather to provide an objective, data-driven aid that allows the designer to assess and evaluate how changes in design parameters can affect safety.
4.4.1.4 Bicycle and Pedestrian Accommodation Development
Per the USDOT Bicycle and Pedestrian Planning, Program, and Project Development Guidance memo: “Providing safe, accessible, comfortable, equitable, and interconnected networks for bicycling and walking creates an integrated, intermodal transportation system that provides travelers with a real choice of transportation modes. Bicyclists, pedestrians, and micromobility users have the same origins and destinations as other transportation system users. It is important for all users to have safe, accessible, equitable, and convenient access to destinations such as airports, ports, ferry services, transit stations and stops, and other intermodal facilities as well as access to jobs, education, health care, and other essential services. Transportation professionals are encouraged to plan, design, construct, and maintain transportation facilities to support complete networks, especially on urban and suburban nonfreeway arterials with posted speed limits less than 50 miles per hour (mph), or to rural arterials that serve as main streets in smaller communities”.
Where these active, non-motorized transportation modes are expected, preliminary plans must be developed to include safe bicycle and pedestrian transportation accommodation. Bicycle and pedestrian design criteria and considerations can be found in the RDM.
Considerations in the design of bicycle and pedestrian accommodations include:
  • Determine if the project location is part of the TxDOT Bicycle Tourism Trials Example Network to determine design requirements for this type of facility;
  • Consult local, regional and District bicycle and pedestrian plans if available (refer to the Active Transportation Plan Inventory webpage);
  • Provide safe accommodations on replaced or rehabilitated bridges by providing accommodation of pedestrians or bicyclist if provided at a reasonable cost;
  • Refer to TAMES/TCAP Toolbox to identify existing ADA barrier information;
  • Coordinate with public transportation providers to facilitate provision of intermodal connections; and
  • Where new bicycle and pedestrian facilities are proposed, include sufficient information to explain the reasons for facility selection in the environmental effects statement.