HDR Engineering of Sioux Falls conducted a traffic study earlier this year in North Sioux City and observed traffic in various areas, including along Northshore Drive and entrances to the schools.

The study states that they observed this location to “identify the demand of vehicles to enter and leave the schools, identify potential conflicts between students and vehicles, identify needed changes in traffic control, and identify other needed roadway changes due to the presence of the schools adjacent to Northshore Drive.”

The observation resulted in the following findings: 1) Lack of left turning lane causes backups as drivers wait to enter the school. 2) At peak times, 10 vehicles can be in que while exiting the school. 3) The city should look into traffic signals. 4) There is a lack of school-crossing signs at crosswalks. After further analysis, HDR determined traffic signals from the elementary and high school driveways onto Northshore Drive are not warranted at this time.

Alternatives that were presented by Jason Kjenstad of HDR at the North Sioux City city council meeting on Nov. 6 showed various ways to reconstruct the Exit 4 interchange and options for Northshore Drive. The following alternatives were presented:

1) Alternative 11 replaces the existing southbound diamond ramps at the I-29/Northshore Drive interchange with a folded diamond configuration. The southbound off-ramp sould be realigned to the west to create a new terminal intersection at Streeter Drive with the southbound off-ramp, but still presents a level of service concerns.

2) Alternative 12 redirects traffic west of the Exit 4 interchange to a new east-west dike road that has been proposed to protect area development from flooding. The proposed dike road would provide direct access to the north side of the school properties further to the west. Traffic from Streeter Drive would be connected directly to Northshore Drive, eliminating the existing intersection.

3) Alternative 13 would create a single-lane roundabout intersection at the southbound ramp terminal at the Exit 4 interchange. The roundabout would allow direct connection of Streeter Drive, eliminating much of the existing delay and enhancing safety.

4) Alternative 14 would improve Northshore Drive to a three-lane section due to the turning traffic and number of driveways. This assumes the dike road alternative is not constructed.

The council discussed the implementation of a continuous left turn lane along the Dakota Valley School. All the options will be kept in mind for future infrastructure and growth plans.

Another intersection that was heavily discussed was the Exit 2 interchange onto River Drive and the area intersections – Streeter Drive, Sioux Point Road, Sodrac Drive, I-29 southbound, I-29 northbound, South Derby Lane and North Derby Lane.

Various alternatives were presented, including reconstructing roads so they connect and create better traffic flow between Dakota Dunes and North Sioux City.

1) Alternative 6 shows two options for re-aligning the frontage road and the Sioux Point Road/Shay Road intersection. The existing intersection creates driver confusion; the proposed intersection will create a cleaner connection between Dakota Dunes and North Sioux City.

2) Alternative 7 shows two options for realigning Sioux Point Road to connect to Sodrac Drive in North Sioux City. The realignment will create a cleaner connection between Dakota Dunes and North Sioux City and will create greater spacing between the collector street intersection and the I-29 interchange at River Drive.

3) Similar to Alternative 7, Alternative 8 shows a realignment of Streeter Drive to connect to Sodrac Drive. The realignment will create a cleaner connection for north-south traffic and will create greater spacing between the collector street intersection and the I-29 interchange at River Drive.

To increase the flow of traffic along River Drive, especially near the I-29 interchanges, HDR suggested installing a median on River Drive around South Derby Lane to prevent left turns.

HDR’s recommendations will be finalized after discussions with their study advisory team and will consist of short-term (zero to five years), mid-term (five to 15 years) and long-term (15 to 25 years) recommendations on what alternatives could best improve the flow of traffic between the communities and within North Sioux City.