Environmental Overview

Based on the analysis and evaluation detailed in the study's Environmental Assessment (EA), this project recently received a “Finding of No Significant Impact” (FONSI). An EA is prepared for projects for which the significance of the environmental impact is not clearly established. The project's Final EA, publicly available online, includes an analysis of a full range of alternatives (including a “no build” alternative) and an assessment of potential environmental impacts through the National Environmental Policy Act (NEPA) process. Through the approval of the EA, the build alternative detailed below was selected to move forward into final design and construction. Public involvement is a crucial element of the EA process.

PURPOSE AND NEED

PURPOSE (WHAT ARE WE TRYING TO DO?)

  • Facilitate congestion  management in the corridor
  • Provide a reliable route for transit
  • Facilitate reliable emergency response 

NEED (WHAT PROBLEM ARE WE TRYING TO ADDRESS?)

PRELIMINARY ALTERNATIVES

Preliminary alternatives evaluated by the 183 North Mobility Project included:

  • GENERAL PURPOSE LANES
    • Standard traffic lanes available for use by all types of vehicles
  • HIGH OCCUPANCY VEHICLE (HOV) LANES
    • Traffic lanes reserved during peak travel times or longer for vehicles with a driver and one or more passengers, including carpools, vanpools and public transit buses
  • EXPRESS LANES
    • Special separated lanes that are designed to remain congestion free
    • Utilize variable toll pricing to manage the amount of traffic in the lane
    • Tolls increase when traffic is heavy and decrease when traffic is light
    • Toll-free for emergency responders, public transit buses, Capital Metro registered carpools and vanpools, MetroAccess vehicles and state and federal military vehicles
  • TRANSPORTATION SYSTEM MANAGEMENT (TSM)
    • Does not increase capacity
    • Low cost strategies enhance safety, manage congestion, and improve traffic flow. Examples include: Ramp metering; Traffic signal synchronization; Incident management; Bus pullouts; Intersection improvements
  • TRANSPORTATION DEMAND MANAGEMENT (TDM)
    • Strategies manage or decrease demand for auto-related travel and/or alternatives to single-occupant vehicles (transit, carpool, vanpool, bicycle)
    • Examples include incentives/disincentives such as: Congestion pricing; High Occupancy Vehicle lanes; Alternative work environments and Telecommuting
  • NO BUILD
    • Proposed improvements would not be constructed; assumes all other projects in the CAMPO Plan would be constructed

RECOMMENDED ALTERNATIVE

The Express Lanes Alternative best meets the Purpose and Need of the project and is the study's Preferred Alternative. It best meets the Purpose and Need of the project by:

  • Using variable toll pricing in special lanes that are separated from the general purpose lanes to keep traffic moving, even if adjacent lanes are congested, by increasing the toll when traffic is heavy and lowering the toll when traffic is light
  • Providing non-tolled, free-flowing, reliable routes and dependable travel times for public transit busses, registered vanpools and emergency vehicles
  • Facilitating reliable emergency response by allowing emergency vehicles to drive toll-free in the Express Lanes, so they can bypass congestion as quickly as possible

AVERAGE TRAVEL TIMES FROM SH 45N TO MOPAC

On average, drivers and transit users in the Express Lanes can expect a reliable nine minute commute during the morning and afternoon peak periods in 2035. Drivers using the general purpose lanes can expect their morning commute to be 24 minutes faster and their afternoon commute to be 16 minutes faster than their commutes would be if no improvements are constructed. Learn more.

EXPRESS LANES TYPICAL CROSS SECTION

The Express Lane Alternative includes extending the 4th general purpose lane southbound from south of Pecan Park Blvd. to MoPac and northbound from Braker Lane to McNeil Drive. This would provide a total of four non-tolled general purpose lanes in each direction continuously between MoPac and SH 45N.

The Express Lane Alternative would also include:

  • More than $5 million for safe connectivity for bicyclists and pedestrians throughout the corridor
  • Direct connectors between RM 620 and US 183 North in both the northbound and southbound directions
  • Lengthened auxiliary lane from the southbound entrance ramp between Oak Knoll Drive and Duval Road in order to improve the merge from the on ramp

ENVIRONMENTAL ISSUES UNDER STUDY

Potential impacts to the following were considered: aesthetic and visual resources, air quality, bicycle and pedestrian facilities, cultural resources, Edwards Aquifer and other water resources, floodplains, geology and soils, hazardous materials, historic and archaeological resources, indirect and cumulative impacts, land use, parkland, traffic noise, vegetation, wildlife, social and community impacts (community cohesion, environmental justice, limited English proficiency populations), surface water (Shoal Creek and its tributaries, Lake Creek and its tributaries, and Rattan Creek), and threatened and endangered species (Ex. Karst invertebrates, Jollyville Plateau salamander)

“The environmental review, consultation, and other actions required by applicable Federal environmental laws for this project are being, or have been, carried-out by TxDOT pursuant to 23 U.S.C. 327 and a Memorandum of Understanding dated December 16, 2014, and executed by FHWA and TxDOT.”

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3300 N. IH-35 Suite 300
Austin, TX 78705

(512) 996-9778 Email Us
Contact Us

3300 N. IH-35 Suite 300
Austin, TX 78705

Call (512) 996-9778
Email Us