Chapter 3: New Location and Reconstruction (4R) Design Criteria
Anchor: #CHDIFBECSection 1: Overview
Anchor: #i1082244Introduction
This chapter presents guidelines applicable to all new location and reconstruction (4R) projects for several different roadway facilities including:
- Anchor: #DNDPBBJR
- Urban Streets; Anchor: #XRBLLRNY
- Suburban Roadways; Anchor: #DTIJLCDC
- Two-lane Rural Highways; Anchor: #AHBDDAWB
- Multilane Rural Highways; Anchor: #UMMYPKXI
- Freeways; and Anchor: #USDHCLIB
- Texas Highway Freight Network (THFN).
For the purposes of this chapter, 4R is defined as projects that either provide a new roadway or reconstruction to upgrade an existing roadway to meet geometric criteria for a new facility. In addition to work described under resurfacing, restoration and rehabilitation, reconstruction work generally includes substantial changes in the geometric character of the highway, such as widening to provide additional through lanes, significant horizontal or vertical realignments, major improvements to the pavement structure to improve long term service, or bridge replacement. Further discussion of this definition can be found in AASHTO's A Policy of Geometric Design of Highways and Streets.
Note that additional vertical clearance requirements may apply to projects on the Texas Highway Freight Network (THFN) if the project criteria as specified in Chapter 3, Section 8 are met.
Departures from these guidelines are governed in Chapter 1, Design Exceptions, Design Waivers, Design Variances, and Texas Highway Freight Network (THFN) Design Deviations, Design Exceptions, Design Waivers, Design Variances, and Texas Highway Freight Network (THFN) Design Deviations.