Cost Range
Three Scenarios
The estimate range reflects unknowns — soil conditions, tree density, and drainage — that site investigation will resolve.
Optimistic
$48,000
$69 / LF
Better soils (CBR>5), lighter woods, owner clears trees, 2 culverts, 10% contingency
Expected
$71,700
$102 / LF
Clay subgrade, heavy woods, 8" base, 3 culverts, 15% contingency as estimated
Conservative
$93,500
$134 / LF
Worst soils (CBR<3, 12" base), very heavy timber, wetland found, 25% contingency
Cost Allocation
Breakdown by Category
Where the money goes. Base and surface aggregate account for nearly a third of direct costs.
Base & Surface
32%
$20,044
General Conditions
19%
$12,000
Clearing & Grubbing
16%
$10,152
Drainage
16%
$9,880
Earthwork
9%
$5,864
Finish Work
7%
$4,400
Contingency
15%
$9,351
Direct Cost
$62,340
Contingency (15%)
$9,351
Estimated Total
$71,691
Detailed Estimate
Line Items
Expand each section to see individual pay items, quantities, and unit prices. All prices include labor, equipment, materials, overhead, and profit.
1.0 General Conditions $12,000
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 1.1 Mobilization / Demobilization | LS | 1 | $4,500 | $4,500 |
| 1.2 Surveying & Staking | LS | 1 | $2,500 | $2,500 |
| 1.3 Erosion Control (Temporary) | LS | 1 | $3,000 | $3,000 |
| 1.4 Traffic Control (approach work) | LS | 1 | $500 | $500 |
| 1.5 Permits & Fees | LS | 1 | $1,500 | $1,500 |
| Subtotal 1.0 | $12,000 | |||
Mobilization covers equipment transport for a small project. Erosion control includes ~300 LF silt fence, straw wattles at drainage points, and a stabilized construction entrance at Cerro Gordo Rd. Permits assume Lane County approach permit ($500–$1,500); no DEQ 1200-C (under 1 acre). Oregon 811 locate is free.
2.0 Clearing & Grubbing $10,152
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 2.1 Clear & grub (heavy woods) | ACRE | 0.51 | $16,000 | $8,160 |
| 2.2 Strip topsoil (6") | CY | 207 | $6.00 | $1,242 |
| 2.3 Dispose of slash/debris | CY | 150 | $10.00 | $1,500 |
| 2.4 Timber credit (salvage) | LS | 1 | ($750) | ($750) |
| Subtotal 2.0 | $10,152 | |||
Heavy woods at $16,000/acre is mid-range for second-growth Douglas fir. Timber credit assumes 1–2 MBF salvaged; could be $0 to $2,000+ depending on tree size and mill demand. Potential savings: If the landowner handles tree removal, clearing cost drops significantly.
3.0 Earthwork $5,864
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 3.1 Excavation (smooth undulations) | CY | 100 | $12.00 | $1,200 |
| 3.2 Fill placement & compaction | CY | 50 | $9.00 | $450 |
| 3.3 Subgrade preparation | SY | 1,004 | $3.50 | $3,514 |
| 3.4 Proof-roll | LF | 700 | $1.00 | $700 |
| Subtotal 3.0 | $5,864 | |||
Earthwork is minimal given the gently undulating terrain. Subgrade prep includes shaping 3–4% crown, moisture conditioning, and compaction. Proof-roll with a loaded dump truck identifies soft spots. If soft spots are found, over-excavation adds ~$15/CY.
4.0 Drainage $9,880
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 4.1 18" CMP cross-drain culverts | LF | 72 | $40.00 | $2,880 |
| 4.2 Culvert end sections (metal) | EA | 6 | $275.00 | $1,650 |
| 4.3 Ditch excavation (V-ditch, uphill) | LF | 700 | $5.50 | $3,850 |
| 4.4 Rock check dams | EA | 4 | $275.00 | $1,100 |
| 4.5 Rip-rap (outlet protection) | CY | 5 | $80.00 | $400 |
| Subtotal 4.0 | $9,880 | |||
Three cross-drain culverts at low points, each 24 LF. 18" CMP is minimum; upgrading to 24" preferred for maintenance access would add ~$720–$1,800. Ditch on uphill side only; if terrain requires both sides, add ~$3,850. Check dams where ditch grade exceeds 3%.
5.0 Base Course $14,896
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 5.1 Geotextile separation (non-woven) | SY | 1,351 | $2.25 | $3,040 |
| 5.2 Aggregate base — delivered (3/4" minus) | TON | 312 | $32.00 | $9,984 |
| 5.3 Aggregate base — place & compact | TON | 312 | $6.00 | $1,872 |
| Subtotal 5.0 | $14,896 | |||
8" aggregate base placed in two 4" lifts, each compacted. Thickness based on assumed CBR < 5. If borings show CBR > 5, base could reduce to 6" (saving ~$3,000). Delivered price assumes ~10 mile haul from Cottage Grove area quarry. Includes quantities for two 40×8 ft passing turnouts.
6.0 Surface Course $5,148
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 6.1 Surface aggregate — delivered (3/4" minus) | TON | 117 | $38.00 | $4,446 |
| 6.2 Surface aggregate — place & compact | TON | 117 | $6.00 | $702 |
| Subtotal 6.0 | $5,148 | |||
3" surface course of well-graded 3/4" minus crushed rock. Higher unit price than base due to tighter gradation spec. Surface aggregate should have adequate fines (5–10% passing #200) for binding without becoming muddy.
7.0 Finish Work $4,400
| Item | Unit | Qty | Unit Price | Total |
|---|---|---|---|---|
| 7.1 Shoulder grading | LF | 1,400 | $1.50 | $2,100 |
| 7.2 Permanent erosion control | LS | 1 | $1,200 | $1,200 |
| 7.3 Seeding & mulching | ACRE | 0.35 | $1,000 | $350 |
| 7.4 Signage & delineation | LS | 1 | $250 | $250 |
| 7.5 Final cleanup | LS | 1 | $500 | $500 |
| Subtotal 7.0 | $4,400 | |||
Shoulder grading on both sides, blending into existing terrain. Seeding uses native seed mix per conservation easement requirements (may be specified by land trust). Permanent erosion control converts temporary BMPs and stabilizes all disturbed slopes.
Quantity Takeoff
Key Quantities
Material and area quantities derived from the 700 ft × 12 ft road prism with 32 ft clearing width and two passing turnouts.
Clearing & Earthwork
Clearing width32 ft
Clearing area0.51 ac
Road prism width20 ft
Topsoil stripping207 CY
Cut volume100 CY
Fill volume50 CY
Aggregate & Fabric
Geotextile1,351 SY
Base aggregate (8")312 tons
Surface aggregate (3")117 tons
Total aggregate429 tons
Estimated truckloads~22
Drainage
Cross-drain culverts72 LF
Culvert end sections6 EA
Ditch length700 LF
Check dams4 EA
Rip-rap5 CY
Design Parameters
Crown slope3–4%
Assumed subgrade CBR3–6
Base thickness8 in
Surface thickness3 in
Passing turnouts2
Turnout size40×8 ft
Value Engineering
Potential Savings
Opportunities to reduce cost, totaling $13,000–$23,000 if all are realized.
Savings Opportunities
Owner-performed clearing$5K–$8K
Timber salvage credit$0.5K–$2K
Better soils (CBR>5)$3K–$5K
Combine w/ nearby work$2K–$4K
Owner hires surveyor$2K–$2.5K
Burn slash on-site$0.5K–$1K
Add-Alternates
Chip seal surface+$7K–$10K
2" HMA (asphalt) surface+$14K–$19K
Third passing turnout+$1.5K–$2K
Dust palliative (MgCl)+$1.5K–$2.8K
Gate at road entrance+$1K–$3K
Schedule
Construction Timeline
Estimated 5–9 working days during the June–September dry season window.
Phase Duration
Pre-construction (survey, erosion control, 811)1 day
Clearing & grubbing1–2 days
Earthwork & subgrade1–2 days
Drainage (culverts & ditch)0.5–1 day
Base & surface aggregate1–2 days
Finish (shoulders, seed, cleanup)0.5–1 day
Total5–9 days
Basis of Estimate
Key Assumptions
This estimate will be refined as site investigation data becomes available. Items marked with risk are the primary sources of cost uncertainty.
- Clay subgrade assumed (Jory/Bellpine series), CBR 3–6 wet. No site-specific borings yet.
- 8" base + 3" surface over geotextile. Designed for CBR < 5.
- No rock excavation. If rock encountered, pricing changes significantly.
- Dry season construction (June–September). Productivity factor 1.0.
- Private work — no prevailing wages, no performance bonds.
- Heavy woods clearing — mature second-growth Douglas fir forest.
- Two passing turnouts (40×8 ft each) included in all quantities.
- Three cross-drain culverts at low points along alignment.
- One-side ditch (uphill side) for full road length.
- Aggregate haul ~10 miles from Cottage Grove area quarries.
- No stream crossings. If needed, add $5,000–$15,000.
- No wetland impacts. If fill required, add permits + mitigation.
- Disturbance ~0.51 acre (below 1-acre DEQ 1200-C threshold).
Contingency Justification (15%)
No soil borings yetHigh risk
No topographic surveyMedium risk
No wetland screeningMedium risk
Conservation easement unknownsMedium risk
Tree density unknownLow–Med risk
WeatherLow risk
Action Items
Next Steps
Complete these items to refine the estimate from AACE Class 4 (−30%/+50%) to Class 3 (−20%/+30%).
-
Get soil data NRCS Web Soil Survey (free, online, immediate) and hand auger borings at 3–5 locations ($500–$1,000 if DIY)
-
Walk the alignment Verify terrain, tree density, drainage patterns, wet areas, and access from Cerro Gordo Road
-
Review conservation easement May impose requirements that affect scope and cost. Get written approval before any disturbance.
-
Get aggregate quotes Call local suppliers (Knife River, Wildish) for delivered prices to Cerro Gordo Rd
-
Get contractor quotes Solicit 2–3 bids from local earthwork/road contractors for comparison
-
Apply for approach permit Lane County Public Works — confirms connection requirements at Cerro Gordo Rd
-
Run desktop environmental checks NRCS, DOGAMI SLIDO, USFWS IPaC — free screenings, ~2 hours total