Practical Design: State Cost Savings by Project

I-95/Route 630 Interchange I-95/Route 630 Interchange

• Original Design - $184M
• Revised Design -  $149M (19% Savings)

The revised design:

• Provided better or equal congestion benefits
• Reduced conflict points from 26 to 14, improving safety
• Reduced number of impacted parcels

I-64 Widening from I-295 to Bottoms Bridge

• Original Design - $79M
• Revised Design - $60M (24% Savings)

Both projects provided the same benefits

I-81 “S” Curves in Buchanan

• Original Design - $38M
• Revised Design - $3M, including future work (92% Savings)

Original design addressed super-elevation over 3 mile stretch of highway.

Revised design:

• Installed lighting chevrons along curves
• Applied high-friction treatment to pavement (only installed in NB direction at time of writing)
• Reduced incidents rate with injuries by 80% [overall?] and incidents with injury by 90% in northbound direction

I-81 Exit 17 Interchange

• Original Design - $157M
• Revised Design - $21M (87% Savings)

Original design addressed:

• Full interchange reconstruction
• Improved level-of-service from E to B

Revised design addressed:

• Realigning existing ramps and adding one new ramp
• Improved level-of-service from E to C

A 2009 1-day Practical Design Workshop worked on applying Practical Design methods to this project.  The goals of the workshop:

• Capture 100% of Value Engineering savings

• Net savings potential 4:1 +/-

• Minimize engineering re-work

The revised project design showed that:

• The original and revised designs were operationally equivalent
• The revised cost was 28% lower