4-to-3 Lane Conversions

All segments were first reviewed to determine the general feasibility of a successful conversion to a three-lane road. The screening examined potential items that will need to be resolved when planning a 4-to-3 lane conversion.

The screening looked at several factors:

• Crash patterns and rates.
• On-street parking.
• Roadway function, such as how much the road is used to access destinations along the road versus through traffic.
• Traffic volumes, including average daily traffic, peak hour volumes, travel direction and turning patterns.
• Transit use.
• Lane utilization.
• Access points and management, including side streets, driveways and retail. When access points are located too closely together, a shared center left-turn lane doesn't work well.
• Roadway width.

No segments were removed from the study after the feasibility screening. The screening showed a few segments would be more challenging to complete, mostly because their high traffic volumes would lead to potential backups and delays. Further study will be needed to determine the full impact on traffic operations and possible constraints.

Improved safety for all road users is the biggest benefit of a 4-to-3 lane conversion when possible. If a road doesn't have the right characteristics, a conversion can actually make safety and operations worse.

All segments were scored to determine which potential conversions would have the biggest benefit, particularly for the safety of pedestrians and bicyclists. The analysis looked at five factors to determine the relative benefits of converting the segment to a three-lane road:

• Access point density.
  Roads with a large number of mid-block access points benefit from conversions because turning vehicles have one less lane to cross. Roads with a higher density of access points were given a higher score.
• Speed.
  Conversions typically help reduce vehicle speeds. The study looked at operational speeds compared to speed limits. Roads where motorists more frequently drive faster - and at much higher speeds - than the posted speed limit were given a higher score.
• Crashes per mile.
  Conversions typically reduce crashes because they reduce the potential crash points. Roads with a higher number of crashes per mile were given a higher score.
• Pedestrian crossing activity.
  Conversions increase pedestrian safety by reducing the number of lanes to cross and creating opportunities for center median island space for pedestrians. Pedestrian volumes were measured using mobile device data, and volumes were based on the number of pedestrians crossing the road, not traveling along one side of the road. Roads with a higher number of pedestrians were given a higher score.
• Bicycle activity.
  Conversions increase bicyclist safety by reducing vehicle speeds and creating opportunities to add bike lanes or buffer space. Bicyclist volumes were also measured using mobile device data, and roads with a higher number of bicyclists were given a higher score. Bicyclists are a high priority for road use, but not all four-lane county roads are appropriate for bicycling or identified as designated bike routes in the county’s bicycle plan.

Pedestrian and bicyclist scores were determined by comparing all road segments in the study against one another.

Each factor was assigned a relative value from one (low) to five (high) based on how it compared to other segments. The overall segment benefit was calculated by averaging the five individual factors.

Together, these benefit scores helped show where a conversion may make sense even if the technical feasibility was lower due to a higher volume of daily traffic or other factors.

Following the technical feasibility and benefits review, five Ramsey County road segments were selected for detailed analysis and concept development. These segments were selected because the technical and benefits analysis showed they may be more challenging to convert.

• County Road C between Lexington Avenue and I-35E.
• Dale Street between Como Avenue/Front Avenue and Highway 36.
• Old Highway 8 between 5th Avenue and County Road D.
• White Bear Avenue between County Road B and Frost Avenue.
• White Bear Avenue between Beam Avenue and Gervais Avenue.

For each segment, a concept road layout was developed to look at how it would function as a three-lane road. The concepts looked at intersection layouts, parking, transit stops and other multi-modal amenities.

Based on these concepts, each segment also went through a more detailed analysis in several areas.

• Crash analysis
  The analysis looked at data from 2016-2019 to examine the top three crash types on each segment and the impact a conversion would have on these crashes. Crash types involving pedestrians and bicyclists were always included, even if they were not one of the top three crash types.
• Operations analysis
  This analysis looked at how traffic flow would be impacted during peak hours. To evaluate turning traffic, the project team used peak hour turning data collected during January and February 2020.
• Parking analysis
  Parking data was collected in January and February 2020 along segments with existing on-street parking. The analysis looked at daytime, evening and overnight parking.
• Cost estimate
  A high-level estimate was developed that factors in road resurfacing, traffic signal revisions and/or replacement, pavement markings, traffic control and overall contingency funds. An estimate was not developed for the two White Bear Avenue segments because they're already planned for future reconstruction.

Detailed analysis for each segment is available beginning on page 14 of the study report and in appendices E-L.