Estimating costs for paved and unpaved greenways that have yet to be studied in detail and/or have align- ments is inexact; these estimates have been created to represent the costs as best as possible to aid decision - makers and the public. The planning level construction cost estimates are typ- ically calculated as a range of costs per mile, with ad- ditional costs assigned as a percentage of the con- struction costs. The additional costs which are consid- ered in these estimates include: Estimating Costs—Paved and Un- paved Greenways
known. Plan assumptions (for cost purposes) in- clude:
• One 10 - foot - wide stream requiring crossing eve- ry three miles • Six percent of the mileage will require board- walking • Wetland impacts will increase costs by an addi- tional 10 percent of construction costs • Floodplain Mitigation impacts will increase costs by an additional 10 percent of construction costs • Other amenities (lighting, wayfinding, benches, etc) are represented by one rest stop per mile at $15,000 each • Design will increase costs by an additional 7.5 percent of construction costs The range of cost estimates per mile and inclu- sive of the items noted above is $290,000 to $390,000 in 2023 dollars. There is a great deal of variability in unpaved greenway costs due to the dif- ferent widths and surface types catering to different types of users. For example, a greenway intended for hikers on foot or people on bikes may be a cleared, natural surface trail 18 inches wide, while a greenway intended for equestrians should be at least five feet wide, requires a higher vertical clearance, and can include crushed shell surface. Cost savings may be seen through using strategies such as materials al- ready on site and volunteer labor assistance.
• • • • •
Design
Floodplain mitigation impacts
Wetland impacts
Crossings – road and water
Boardwalks
• Signage, lighting, and other amenities
Other additional costs that apply to individual green- ways once alignments have been determined and not included in these estimates include: • Land acquisition , which can be very high and sometimes represent a cost higher than construc- tion. These costs cannot be known until a detailed alignment and design effort is complete. However, most projects in this plan are mainly on public lands. • Bridges, retaining walls, and other structures , which can be 40 - 50 percent of a project ’ s cost. They cannot be known until a corridor feasibility study or detailed design effort is complete. Costs for stream crossings have been estimated, but not larger bridge structures. • Maintenance and operations costs , which are typically tied into an annual budget allocation. They vary by trail surface, trail location, and envi- ronmental factors. The range for the paved greenways was developed by collecting cost data for greenway projects either re- cently built or designed with detailed costs in Hills- borough and Pinellas Counties. The range of costes- timates, per mile and inclusive of the items noted above, is $1.4 - 2.2 million per mile of paved greenway in 2023 dollars. The planning level costs for unpaved greenways were developed through best practices research and exist- ing costs identified by the County ’ s implementing agencies. Since these greenway projects are currently concepts without alignments, the details that will im- pact actual costs, as mentioned previously, are un-
Costs Per Mile (Paved Greenway)
Costs Per Mile (Unpaved Greenway)
$1.4 - $2.2 million (2023 dollars)
$290,000 - $390,000 (2023 dollars)
HILLSBOROUGH COUNTY GREENWAYS AND TRAILS MASTER PLAN
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