Polacca Highway Estimate — Case Study

Project Overview

Turning drawings, specs and geotechnical data into a buildable, defensible highway estimate.

This estimate was prepared as part of the CON 486 – Highway Construction Estimating course at Arizona State University. Working from ADOT-style bid documents – including drawings, bid schedule, special provisions and a geotechnical report – I developed a bottom-up estimate for the widening of SR 264 near Polacca, Arizona.

Separated direct, indirect and markup components.
Built crew-based production for demo, trucking, utilities, aggregate base and paving.
Balanced bid items after productivity and constructability review.
Structured allowance for schedule, traffic and geotechnical risk buckets.

Scope at a Glance

Demo & Grading: removal, re-grading and preparation of the widened roadway section.
Trucking & Haul: import / export of materials using distance- and time-based haul cycles.
Utilities & Drainage: culverts, stormwater improvements and utility adjustments.
Aggregate Base & Paving: sub-base, base course and asphalt placement / compaction.
Indirects: traffic control, mobilization, field supervision and project overhead.

Total Direct Cost

$841,826.08

Labor, owned / rented equipment, materials and subcontracted work for all bid items.

Total Indirect Cost

$345,194.36

Field office, traffic control, supervision, insurance and project overhead.

Balanced Bid Price

$1,395,795.75

Final balanced bid after productivity checks and risk review.

Risk / Contingency

$247,943

Structured contingency allocated to schedule, traffic and geotechnical risk buckets.

$1.16M

Direct Cost Mix

How labor, equipment, materials and allowances build the $1.16M direct cost.

Materials

$354,405.73

Subcontract

$281,994.22

Allowance / Risk Pool

$247,943.00

Labor

$159,502.55

Owned Equipment

$82,511.55

Fees

$26,315.76

Rented Equipment

$12,000.00

Cost Breakdown by Category

How the highway cost is distributed across labor, equipment, materials, subcontractors and risk.

Materials $354,405.73

Subcontract $281,994.22

Labor $159,502.55

Owned & Rented Equipment $94,511.55

Fees: $26,315.76 • Allowance / Risk Pool: $247,943.00
All values are taken from the final estimate summary and cost breakdown structure.

Highway construction crews working within a live traffic corridor

Risk & Contingency Logic

Why the estimate carries a structured $247,943 risk pool instead of a flat percentage.

Schedule & Phasing Risk

$92,000

Night work, lane closures and productivity loss.

Conservative production rates were used for demolition, trucking and paving under constrained traffic windows. Change-of-sequence and erosion risk were captured in this bucket.

Traffic & Safety Risk

$68,000

Work-zone incidents, detours and MOT changes.

Covers potential redesign of maintenance-of-traffic, added flagging hours, temporary barriers and additional safety measures requested by the owner.

Geotechnical & Quantities Risk

$87,943

Soil behavior, unsuitable material and quantity growth.

Based on the geotechnical report and earthwork assumptions, this amount protects against under-cut, soft spots, moisture conditioning and unanticipated subgrade repair.

Highway construction earthwork and paving

Key Deliverables

Final estimating documents prepared from the Polacca highway bid package.

SR 264 Polacca Highway Widening — Bid & Estimate