Traffic study finds Old Ridge Road near two-lane capacity; consultant recommends multi-lane sections and roundabout changes

Scott Cothern, a traffic consultant with Skipper Consulting, told the Prattville City Council that the Old Ridge Road corridor already shows significant peak-hour queuing and that planned development would push some segments to or beyond typical two-lane capacity.

Cothern said his team used drone photography, tube counts and turning-movement counts to build a baseline and that field observations showed heavy queuing at the southbound approaches near the roundabout and at the Old Farm Lane intersection. He reported counts of about 415 morning left-turn vehicles at one intersection versus 35 at another, and explained that a single left-turn lane approaches operational limits north of roughly 300 vehicles per hour.

Using standard trip-generation estimates, Cothern told the council the Glenbrook residential buildout phases would add roughly 3,000 daily trips (two phases of about 150 lots each), Central Alabama Community College would contribute about 800 daily trips and a proposed high school on Old Ridge Road would add roughly 1,600 daily trips. Combined, those increases would add about 5,400 daily trips to the corridor and, with other growth, put segment volumes near the engineering threshold for converting a two-lane road to more lanes (Cothern cited roughly 17,000 daily vehicles as a typical two-lane limit).

"If you combine that with the residential additions and the community college information, we're gonna add about 5,400 new trips to the Old Ridge Corridor," Cothern said, summarizing the study's projection and the consequence for capacity planning.

Cothern presented five primary recommendations: a five'lane cross section on Old Ridge Road between Fairview and the proposed Laney Drive roundabout (including a northbound pass'by lane and a southbound outside lane), modification of the roundabout to a partial multi'lane configuration to favor through traffic on Old Ridge Road, conversion to a three'lane (one north, one south and a two'way left'turn lane) cross section between the fire station and Bluegrass Drive, an added southbound left'turn lane on the far west end where development demands it, and alignment/coordination with Laney Drive improvements being built by others.

On cost, a council member relayed a staff estimate in the range of $7'$8 million for the recommendations Cothern described, noting that this number excluded work on Highway 31. City and county jurisdictional boundaries complicate funding paths: Old Ridge Road is functionally classified as a local road in places, and state or federal funding typically requires collector classification or ALDOT involvement for state routes. "It has to be classified as a collector road" before certain federal or ALDOT funds can be used, a council member said.

Cothern and council members also discussed operational alternatives and ALDOT policy: extending turn lanes at the Old Ridge/31 offset and the limits of getting a traffic signal warranted on a state route (ALDOT typically requires a broad, multihour need, not just a peak'hour problem). The consultant said some roundabout routing tweaks could be implemented to shift traffic away from Old Farm Lane onto Old Ridge Road and that the proposed cross sections and partial multi'lane roundabout would preserve acceptable levels of service when combined with the known growth.

Next steps described to the council included further design detail, cost refinement (surveying, utility work and right'of'way add to preliminary estimates), and coordination with the county and ALDOT where jurisdiction and classification require it. The council signaled it would use the study as part of any decision about supporting a high school at the Old Ridge Road site.