Review bicycle and pedestrian facilities as part of the 161^st Avenue Street Reconstruction

Purpose:
The purpose of this case is to discuss potential alternatives for creating bicycle and pedestrian facilities as part of the 161^st Avenue Reconstruction, Improvement Project #23-01.
 
Background:
City Improvement Project 23-01 proposes to reconstruct 161^st Avenue between Armstrong Boulevard and Variolite Street. The street totals approximately 2,700 lineal feet (0.51 miles) in length, 29 feet wide as measured to the face of curb, with bituminous curb. No parking is allowed on either side of the street.  The existing right-of-way is 66-feet wide throughout.  
 
Project History

• 2022 – 2031 Capital Improvement Program – listed as street reconstruction for 2024
• April 12, 2022 City Council accepted proposals for topographic survey

 
Pavement History
161^st Avenue was constructed in 1979. Pavement maintenance records indicate the street received crack seal / seal coat improvements in 1993 and 2009, and a pavement overlay in 2001. City maintenance crews have performed patching over the last several years, and the bituminous curb is quite deteriorated.
 
Ground Penetrating Radar (GPR) was performed on the street segment, finding an average bituminous thickness of 3.4 inches and aggregate base thickness of 3.2 inches.
 
Planned Street Improvements
161^st Avenue is a Municipal State Aid (MSA) street, and must comply with State Aid design requirements, including conforming to a 10-ton design. Staff needs to obtain geotechnical evaluations prior to determining the required pavement thickness, though does know the existing pavement section is not sufficient to meet a 10-ton design. The right-of-way adjacent to Central Park is proposed to remain as is at 66-feet wide, but along the PACT Charter School / Saint Katherine Drexel Church property the right-of-way is proposed to increase to 80-feet wide. 
 
Bicycle and Pedestrian Facilities
Staff has reviewed several potential options for including bicycle and pedestrian facilities as part of the 161^st Avenue reconstruction. The various options can have a large impact to the project scope, estimated costs, and trees within the project corridor. For all the options listed, Staff proposes to keep 161^st Avenue as no parking in both directions, use concrete curb and gutter, add storm sewer and/or ditch flumes, maintain the 30-mph posted speed limit, assume future ADT to be between 2,000 and 5,000, and follow State Aid requirements for lane width(s) and curb reaction(s). Additionally, any trail connections would tie into the existing trail off the park drive, avoiding the 161^st boulevard area in-front of the parking lot.
 
For tree removal and impact requirements, Staff assumed any tree within 2 feet of a proposed improvement would require removal, and any tree within 6 feet of an improvement would have a significant impact to the root system. Trees with significant impacts to the root system are often compromised and die over a period of years.
 
Alternative 1: 2 Lane Road, Standard 6’ Boulevard, Standard 10’ Off-Street Trail

• 28-foot wide road (12’ travel lanes, 2’ curb reactions)
  • Shift the road 1-foot south (existing road is 29 feet wide)
• Central Park Impacts
  • Removal of 38 of 39 trees in the boulevard area
• PACT / Church Boulevard Impacts
  • Estimated Removal of 55 trees in the boulevard area
  • Root Impact of 4 trees in the boulevard area
• Existing Properties on south side of 161^st Avenue
  • Standard impacts to driveways and grading to add new curb and gutter and storm sewer
  • No anticipated impacts to trees

 
Alternative 2: 2 Lane Road, No Boulevard, 12’ Off-Street Trail behind curb

• 28-foot wide road (12’ travel lanes, 2’ curb reactions)
  • Shift the road 1-foot south (existing road is 29 feet wide)
  • 12’ Trail includes 10-foot standard trail plus required 2-foot clear zone area
• Central Park Impacts
  • Removal of 14 trees in the boulevard area
  • Root Impact of 24 trees in the boulevard area
• PACT / Church Boulevard Impacts
  • Estimated Removal of 23 trees in the boulevard area
  • Root Impact of 35 trees in the boulevard area
• Existing Properties on south side of 161^st Avenue
  • Standard impacts to driveways and grading to add new curb and gutter and storm sewer
  • No anticipated impacts to trees

 
Alternative 3: 2 Lane Road, 10’ Off-Street Trail between trees and ball fields

• 28 feet wide road (12’ travel lanes, 2’ curb reactions)
  • Trail placed 3 feet south of the foul poles and south of lighting
    • Moving trail further north would require moving foul poles and lights
    • Fields would have to move to maintain 300-foot ball field dimensions
• Central Park Impacts
  • Removal of 13 trees in the boulevard area
  • Root Impact of 12 trees in the boulevard area
  • Avoided Impact to 14 trees in the boulevard area
• PACT / Church Boulevard Impacts
  • Potentially avoids impacts to boulevard trees
    • Dependent on layout of school and future church properties
• Existing Properties on south side of 161^st Avenue
  • Standard impacts to driveways and grading to add new curb and gutter and storm sewer
  • No anticipated impacts to trees

 
Alternative 4: On Road Bike Lanes

• 36 feet wide (12’ travel lanes, 6’ bike lanes each side)
  • Widens road by 7 feet
  • No additional off-street facilities
• Central Park Impacts
  • Between Armstrong Boulevard and East Park Entrance
    • Removal of minimum 2 trees
    • Root Impact of 16 trees
  • Between East Park Entrance and East Property Line
    • Removal of 4 trees
    • Root Impact of 10 trees
    • Avoided Impact to 25 trees in the boulevard area
• PACT / Church Boulevard Impacts
  • No tree removals noted
  • Root Impact of 15 trees in the boulevard area
• Existing Properties on south side of 161^st Avenue
  • Higher driveway and grading impacts due to curb and gutter in the existing boulevard area
  • No tree removals noted
  • Anticipated moderate root impact to numerous trees along the corridor
    • Depending on ability to match grading

Alternative 5: No Addition of Bicycle and Pedestrian Facilities

• 28-foot wide road (12’ travel lanes, 2’ curb reactions)
  • Generally minimal impacts to trees along the corridor

Staff estimates up to 15 minutes will be needed to present this case and respond to questions.

Observation:
All alternatives which include an off-street trail will have a significant impact to the existing trees in Central Park. The option of on-street bike lanes does impact a number of existing trees, but significantly fewer; however, the on-street bike lanes is not the optimal solution for pedestrians. Additionally, if trees are removed, Staff would like input if tree replacement and/or landscaping should be included as part of these improvements.
 
The alternatives listed do not anticipate significant impacts to trees on the south side of 161^st Avenue, which includes 9 properties, 7 of which are heavily wooded along the right of way. It should be noted tree removal will be required within the 20-foot wide drainage & utility easement between 7852 and 7826 161^st Avenue to accommodate storm sewer improvements. Additional tree removal may be required due to grading requirements in the ponding area in the rear yard of 7826 161st Avenue and 7833 159^th Lane.

Funding for 161^st Avenue reconstruction and any trail construction is proposed to come from MSA Funds.

Storm sewer improvements are proposed to be funded from Stormwater Utility Funds and/or MSA Funds.

Staff recommends Alternative #1 – reconstructing 161^st Avenue as a minimum width 2 lane road with a 6-foot boulevard and 10-foot bituminous trail on the north side.

Motion to accept one of the identified alternatives, or reject all alternatives and provide alternative direction.