 Montana Demonstration Project: Innovative Culvert Rehabilitation Using Trenchless Technologies
Economic Analysis
Based on the information furnished by MDT, the cost for the innovative trenchless technologies used on this project were about $75,000 higher than the costs for traditional subexcavation and pipe replacement. Because this was the first time MDT employed such innovative features to rehabilitate pipes, the agency chose a project on a highway with lower ADT to gain experience. In higher trafficked areas where lane closures and traffic delays are not permitted, the trenchless technology could eliminate interference with traffic flow and be economically feasible by resulting in much lower user costs.
For this economic analysis, MDT supplied the costs for both methods of rehabilitating the pipes, as shown below.
| Estimated Cost for Subexcavation and Replacement |
| 1,419 linear feet (LF) of 24-in drainpipe at $85.00/LF |
= $120,615.00 |
| 322.2 yd3 of CBC at $30.00/yd3 |
= $9,666.00 |
| 83.4 tons of commercial plant mix at $125/ton |
= $10,425.00 |
| 20 days of traffic control at $2,500/day |
= $50,000.00 |
| Road user cost |
= $3,500 |
| Total |
= $194,206.00 |
| Actual Costs for Pipe Lining |
| 661 LF 24-in pipe liner at $190/LF |
= $125,590.00 |
| 758 LF 18-in pipe liner at $190/LF |
= $144,020.00 |
| Traffic control (two temporary signs) |
= $14.00 |
| Total |
= $269,624.00 |
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