1. Sand Mining Road and Traffic Impacts
Planning Commission
August 8, 2016
David F. Kramer, P.E.
Winona County Engineer
This presentation is available at the Winona County website under Departments > Highway & Land Survey > Highway > Reports and Documents or

2. Roadway Impacts On: Traffic Congestion Safety Concerns
Pavement Deterioration
On:
State Highways (Interstate, U.S., Mn Highways)
County Highways aka County Roads
County State-Aid Highways (state-aid & local funding)
County Highways (local funding only)
City Streets
Town Roads
Gravel – mine operator typically maintains while they use.

3. Traffic Congestion & Safety
Focus is typically intersections and access points.
Specific to a haul route and proposed volume.
Typically
Study and report by traffic engineer.
Developer or mine operator pays for necessary improvements, such as
Turn lanes or bypass lanes
Access modifications

4. Example – Nisbit Mine
Traffic study by Wenck Associates analyzed five intersections.
Paid for by applicant.
Scope and report reviewed/approved by County Engineer.
Inadequate sight distance at the Gathje Lane entrance onto County Rd 113 (to the north)
Temporary access was constructed to a field drive with adequate sight lines.

6. Pavement Impact
One legal 80,000 pound GVW tractor-trailer truck does as much damage to road pavement as 9,600 cars.
Source: Highway Research Board, National Academy of Sciences, 1962
All trucks (not just hauling sand).

7. Pavement Impact
Primary focus of discussions during 2012 Winona County moratorium.
Any incremental increase in costs, if not collected from mine operations, will be borne by local taxpayers.

8. Williston, North Dakota experience.
NBC, Rock Center with Brian Williams, November 4, 2011

10. February 2012
Proposed Sand Mines

11. 21.5 Miles on County Roads

12. What are others doing about this?
We queried County Engineers for the other 86 Minnesota counties.
Multiple conversations with southeastern MN and western WI counties.
Chippewa County, WI has been dealing with this for a couple years, and has road use agreements that have been a template for other WI counties.

13. Paying for Pavement Impacts Things Considered & Discussed
Additional road use taxes already collected.
State-aid highways – use state-aid funds.
Aggregate tax
Bond – not a funding source; just insurance.
Impact fee per road use agreement
Identify improvements & pay upfront
Similar to Chippewa County, WI agreements
ESAL-mile & pavement cost consumed
Similar to Jackson Co, Mn & Mn LRRB methodologies

14. ESAL – Equivalent Single Axle Load
ESAL Defined: One ESAL represents a single standardized load application. Each ESAL is known to cause a quantifiable and standardized amount of damage to the pavement structure equivalent to one pass of a single 18,000-pound, dual-tire axle with all four tires inflated to 110 psi.
Source: Alaska Flexible Pavement Design Manual.

15. What is an ESAL? 18,000 lb axle weight
This vehicle simplifies the explanation of an ESAL.
18,000 lb axle weight

16. THE CALCULATIONS If you think this equation is complicated…It is
Generalized Fourth Power Law
Flexible Pavement ESAL Equation
Bases of the ESAL calculation. Any axle configuration can be converted to an ESAL.

17. ESAL Typical Load Equivalency Factors
Axle Type
Axle Load
Load Equivalency Factor (from AASHTO, 1993)
(kN)
(lbs)
Flexible
Rigid
Single axle
2,000 10,000 14,000 18,000 20,000 30,000
Tandem axle
2,000 10,000 14,000 18,000 20,000 30,000 34,000 40,000 50,000

18. Assumptions for Funding Scenario
Based on typical existing pavements with current 500 ADT and designed for 110,529 ESALs; pavement cost based on reclaiming and asphalt paving at $200,000/mile.
2 sand mines; = 130 truckloads/day; 6 days/week; 7 months/yr; 23 tons on 80,000 lb truck that is 2.4 ESALs; trucks travel 10 miles on county roads.

19. Paving New Asphalt Over Reclaimed Asphalt
Approximately $200,000 per mile. [used in 2012 calculations]
2016 cost is $320,000 per mile including some culvert repairs.

20. Funding Scenario February 7, 2012 presentation to Winona County Board
Aggregate Tax
Note 5
1 Assuming 23 Tons on an 80,000 lb semi that is 2.4 ESALs.
2 Assuming 10 miles on County Roads (County Highways and County State-Aid Highways).
3 Assuming 2 mines, = 130 truckloads/day; 6 days/week; 7 months/yr; 23 tons/truck.
4 Based on 2012 levy $16,972,674.
5 Aggregate Tax amount per ton to the County Road & Bridge Fund is $ per ton.
6 Based on current traffic of 500 vehicles per day; 20-year design; traffic grows to 550 vehicles/day during the 20 years.

21. Example Roadway Surface Costs for Sand Mining Haul Routes
Information for the Winona County Committee of the Board
March 6, 2012
Prepared by David Kramer, Winona County Engineer
$0.23/ton/mile, from Minnesota Local Road Research Board, Traffic Impact Calculator Tool
Based on the Major Traffic Generators Impact Tool spreadsheet at using default spreadsheet values and actual pavement design data from 2006 CSAH 6 and CSAH 33 repaving project plans in locations of plausible haul routes. Using calculation method 1 of 3, the “GE Difference Method.” Based on 300,000 tons of sand hauled; 23 tons/load on 80,000 pound gross-weight trucks; 13,043 loads.
$0.22/ton/mile, from the funding scenario in the February 7 presentation to the County Board
The funding scenario had an interim calculation of $0.19 cost/mile/ton. Based on a construction cost of $200,000/mile to reclaim and pave an asphalt roadway; based on a pavement design of 500 vehicles/day; 20-year design; traffic grows to 550 vehicles/day during the 20 years; 20-year design ESALs of 110,529; 23 tons/load on 80,000 pound gross-weight trucks that are 2.4 ESALs. The $200,000/mile cost is for the construction contract only. Adding 16% for preliminary engineering and construction engineering gives a cost of $0.22/ton/mile.
$0.25/ton/mile, Buffalo County, WI draft road use agreement.
In a draft road use agreement that had been verbally agreed to but as of February 13, 2012 had not been signed. Based on $1.00/ton; 4 mile segment of County Rd P impacted; $250,000/mile project necessary to upgrade the road to handle the mine traffic.

22. Roadway Impact Fee approved by Winona County Board April 24, 2012 (Vote: Yes 5)
In addition to identified improvement costs per the final approved traffic impact analysis, a Roadway pavement impact fee shall be required of $0.219 (Jan 2012) per ton per mile, with the rate adjusted annually on January 1 to account for inflation using the Engineering News Record Construction Cost Index. Tons are net tons of material hauled in the primary hauling direction. Return of empty trucks or backhauling a fraction of the primary haul will not be counted if the return route follows the reverse route of the primary hauling direction. Per mile means per mile of paved public roads, not including trunk highways under the jurisdiction of the Minnesota Department of Transportation. The $0.219 per ton per mile is based on a construction cost of $200,000 per mile to reclaim and pave an asphalt roadway; including 16% for preliminary engineering and construction engineering the project cost is $232,000 per mile. Based on a pavement design for 500 vehicles/day; 20-year design; with traffic growing to 550 vehicles/day during the 20 years; 20-year design ESALs of 110,529; $2.099 per ESAL per mile. Based on 23 tons per load on 80,000 pound gross-weight trucks that are 2.4 ESALs; $0.219 per ton per mile. Winona County recognizes the presence of historic industries such as agricultural services, manufacturing and distribution as being accommodated by current public infrastructure and therefore it reserves the right to impose road impact exactions exclusively on new infrastructure-dependent industry having a disproportionate impact on county infrastructure due to a combination of high vehicular weight and traffic volume as determined by the Planning Commission and County Board. Any and all fees collected will be used exclusively for the purpose intended, not co mingled with any other funds, and refunded on a prorated basis should it be determined that the funds are over and above the amount needed for the intended purpose.

23. Summary
Intersection and safety impacts are typically identified in a traffic study, with the mine operator paying for necessary improvements.
Local road pavement deterioration can be addressed through an exaction (Winona County fee model) or an agreement where the mine operator pays for necessary improvements (Chippewa County model).