Here's the layout of the Costco development at Lincoln Road and 25 East (Hitt Road). |
Going by the Transportation Impact Study prepared for the city of Idaho Falls and Bonneville County by Kittelson & Associates, it looks like the roundabout, expanded in 2018, will remain. Kittelson is recommending three access points -- one on Lincoln and two on Hitt.
The full report can be found here -- TRANSPORTATION IMPACT STUDY | Idaho Falls Costco -- but if you'd rather not scroll through 71 pages here are the passages we found most informative.
Proposed Development Plan
▪ Kittelson maintains a database of traffic data and travel characteristics for Costco Wholesale. This information was used to estimate the trip generation for Costco Wholesale during the weekday PM and Saturday midday peak hours.
o The proposed Costco warehouse and fuel station and outparcel are estimated to generate 7,045 daily net new trips, 707 weekday PM peak hour net new trips, and 988 Saturday midday peak hour net new trips.
▪ The distribution pattern for site-generated trips was estimated based on Costco Wholesale’s prediction of potential members in the area, a review of the proposed access locations and adjacent roadway system, existing traffic patterns, and insights from the City and County staff.
▪ The proposed development plan includes two access points on 25th East and one access point on Lincoln Road. For initial analysis purposes, these three access points were assumed to be unsignalized, full-movement accesses.
Off-Site Intersections
▪ No improvements are recommended at the off-site intersections as part of the Costco warehouse and fuel station development. ... The results of the study indicate that the proposed Idaho Falls Costco can be constructed while maintaining acceptable traffic operations and safety at the study intersections, assuming the recommended mitigation measures are in place.
Site Access Intersections
▪ Site Access A/Lincoln Road -- Construct a full-movement, unsignalized access at Site Access A on Lincoln Road that includes one ingress lane, two egress lanes (southbound left-turn and right-turn lanes),and a westbound right-turn lane.
▪ Site Access B/25th East -- Construct a full-movement, unsignalized access at Site Access B on 25th East that includes one ingress lane, two egress lanes (eastbound left-turn and right-turn lanes), and a southbound right-turn lane at the opening of Costco, plan for a future multilane roundabout at this driveway by reserving the space needed for a multilane roundabout design, and participate in a cost-sharing of the roundabout. The multilane roundabout would be installed at a future date when deemed necessary by traffic volumes, traffic operations at this driveway, and development of the property to the east.
▪ Site Access C/25th East -- Construct a full-movement, unsignalized access at Site Access C on 25th East that includes one ingress lane and one egress lane (shared westbound left-turn and right-turn lane).
▪ Maintain adequate sight distance at Site Access A, B, and C by limiting the shrubbery and landscaping.