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Project Description

Purpose

The main purpose of this project is to increase capacity and safety on the 94-mile long IH 35 corridor through the Waco District.

Why?

• Roadway system is forty/fifty years old (see original design guidelines)
• Traffic is growing very fast
• More trips at higher speeds
• More vehicles per family
• More truck traffic than in the 1950s
• More NAFTA traffic
• Discontinuous frontage roads
• Pavement and bridges are wearing out

Must, Need, Like

During the process of increasing capacity along IH 35, there are several areas that will be addressed. These can be divided into three types of improvements:

1. things that MUST be done,
2. things that NEED to be done, and
3. things that TxDOT would LIKE to be done along the corridor.

Must Be Done

Horizontal Alignments

Curves to the left or right as you drive along IH 35 must not be too sharp to safely drive at a safe speed. Curves that are too sharp increase the likelihood that a car will drive off the road or into oncoming traffic on the outside of the curve.

Vertical Alignments

Crest Curves

Vertical curves, or hills and valleys, must be designed so that drivers can see and avoid objects or stopped vehicles on the roadway. On hills, or “crests,” drivers must be able to see over the tops of the crests far enough to have enough time to stop if they need to.

Sag Curves

Likewise, in valleys, or “sags,” drivers must be able to adequately see the end of their headlight beams on the road to avoid obstructions in the roadway.

Clearance

A vertical clearance of 16’ 6” above the roadway must be provided for trucks.

Clear Zones

Areas beside all roadways, including frontage roads, must be provided free of obstructions so that if a vehicle leaves the road, it will not hit anything dangerous. These “clear zones” vary in width based on speeds and whether the road has curbs. Basically, a 30’ clear zone must be provided if the road has shoulders, and 1’ 6” must be provided behind the face of the curb.

Need To Be Done

Concrete Median Barrier

A continuous barrier needs to be provided between the northbound and southbound mainlanes of IH 35. This will help prevent accidents where a vehicle crosses the median into oncoming traffic. It may also allow widening of the IH 35 mainlanes toward the center of the road, thus reducing the need for widening the facility toward adjoining property and reducing the need for additional property to be acquired for highway right of way.

One-Way Frontage Roads

As traffic increases, the two-way frontage roads need to be changed to one-way to make the roadway safer. One-way frontage roads need to be provided throughout the 94 miles of IH 35 in the Waco District. Two-way frontage roads can be confusing to those not familiar with their use and can result in head-on collisions.

Continuous Frontage Roads

Continuous frontage roads along IH 35 need to be provided. There are several locations now where the frontage roads are discontinuous, examples include the Brazos River, railroads and several interchanges. Providing continuous frontage roads reduces the number of vehicles on the mainlanes of IH 35. With continuous frontage roads, traffic can be redirected onto the frontage roads to bypass a mainlane accident, construction or other problem area.

Ramps

Throughout the 94-mile IH 35 corridor, the entrance and exit ramps need to be converted to an “X” pattern in as many locations as possible. X pattern ramps provide several advantages over “Diamond” or “Y” pattern ramps. X pattern ramps allow most of the traffic from adjoining property to enter the mainlanes of the freeway without going through an intersection with the cross street. It also allows traffic exiting from the freeway a longer distance to move into the right lane of the frontage road to turn right at the next cross street.

"Diamond" or "Y" Pattern Ramps

"X" Pattern Ramps

Like To Be Done

Aesthetic / Visually Pleasing Design Elements

TxDOT would like to include interesting and appropriate design features into the redevelopment of IH 35. Examples are placing “signature” features on bridge columns, bridge rails and retaining walls. These signature features could tie in prominent local items to give the corridor a true Central Texas look.

Intelligent Transportation Systems (ITS)

TxDOT would like to include ITS features into the IH 35 corridor. Items like changeable message signs, highway advisory radio, roadway cameras and the use of the Internet can provide valuable information to the highway user in planning trips.

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