I-29 Exit 71 Interchange Alternative Summary
This table shows the comparison of compressed diamond, single point, and diverging
diamond interchanges in terms of Level of Service, predicted safety, construction
duration and maintenance of traffic, potential environmental impacts, and
right-of-way
and costs.
To view the table full screen, click here.
Alt. | Discription | 2050 Planning Horizon Traffic Operations | Interchange Year of LOS D | Predicted Safety (2028-2050) | Construction | Potential Environmental Impacts | ROW & Costs | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Interchange LOS | SB RTI LOS | NB RTI LOS | 2/3-Lane Section | 4/5-Lane Section | Fatal & Injury Crashes | Total Crashes | Duration | Interchange Maintenance of Traffic Rating | WAPA, Wetlands and Floodway | ROW Acquisition | Construction + ROW + Contingency Costs | ||
AM / PM | AM / PM | AM / PM | 5-Year Range | 5-Year Range | % Increase (+) or Decrease (-) from No Build | % Increase (+) or Decrease (-) from No Build | Seasons | 10 – Most access 1 – Least access | Potential Impacts and Acres | Acres | $ M | ||
1a | Compressed Diamond I-29 Under |
A / A | B / B | A / A | 2090-2095 | Beyond 2105 | -19% | -19% | 1.5 | 8 (on alignment) 10 (offset) |
Wetlands: 4.6 ac Floodway: 0.08 ac |
0.7 | $20.5 |
1b | Compressed Diamond I-29 Over |
A / A | B / B | A / A | 2090-2095 | Beyond 2105 | -19% | -19% | 2.5 | 3 |
WAPA transmission lines Wetlands: 5.7 ac Floodway: 0.12 ac |
0.4 | $25 |
2a | SPI I-29 Under |
B / B | B / C | - | 2080-2085 | 2080-2090 | -21% | -18% | 2 | 8 |
Wetlands: 2.9 ac Floodway: 0.06 ac |
0.4 | $33 |
2b | SPI I-29 Over |
B / B | B / C | - | 2080-2085 | 2080-2090 | -21% | -18% | 2.5 | 0 |
WAPA transmission lines Wetlands: 4.4 ac Floodway: 0.09 ac |
0.4 | $29.5 |
3a | DDI I-29 Under |
B / B | B / B | B / B | 2085-2090 | Beyond 2105 | -19% | -16% | 2 | 10 |
Wetlands: 5.8 ac Floodway: 0.10 ac |
1.5 | $25.5 |
3b | DDI I-29 Over |
B / B | B / B | B / B | 2085-2090 | Beyond 2105 | -19% | -16% | 2.5 | 3 |
WAPA transmission lines Wetlands: 7.0 ac Floodway: 0.14 ac |
1.5 | $30 |
NB | No Build | D / D | F / F | A / A | By Year 2050 | - | Baseline (154) | Baseline (469) | - | - |
Wetlands: 0 ac Floodway: 0 ac |
0 | 0 |
Approximate ‘Alignment Option’ ROW acquisition and cost adjustments:
- Shifted south 6’: +0.6 acres ROW; +$1.0M
- Shifted south 55’: +1.8 acres ROW; +$1.5M
- Shifted south TBD’: +TBD acres ROW; +$TBDM