(Includes 2,425 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.0 min

New Construction

Construction Length: 3.4 miles

Structures:

• Walls: Unknown
• Tunnel: Yes
• Bridges: 1

Length Within Parks: 1 mile

Construction Footprint: 77 acres

Construction Schedule: 4 years

Watershed Crossings

Wilson Creek: 1

Estimated Construction Cost in 2019 $ (Millions)

$672M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 54 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 1 acre

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the dark pink segment with yellow border indicates the approximate position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

Travel Time Added (minutes)

Added Time: 0.8 min

New Construction

Construction Length: 3.5 miles

Structures:

• Walls: Unknown
• Tunnel: No
• Bridges: 2

Length Within Parks: 0.9 miles

Construction Footprint: 80 acres

Construction Schedule: 3 years

Watershed Crossings

Wilson Creek: 2

Estimated Construction Cost in 2019 $ (Millions)

$300M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 56 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 3 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 0.2 min

New Construction

Length: 3.7 mi

Footprint: 92 acres

Schedule: 2 years

Cost (in Millions)

Minimum: $340M

Maximum: $400M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 67 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 3 acres

BASIS FOR ALTERNATIVE EXCLUSION

The Project stakeholders and the project development team agreed in late 2018 to eliminate the three C alternatives from further study for the following reasons:

1. The Expert Risk Assessment estimated that these alternatives have a high risk of geotechnical failure. The risk of building these alignments is higher than staying on the current alignment and making improvements as alternative X would do.
2. The C alternatives have no unique environmental benefits.
3. The C alternatives are high cost and have high environmental impacts.



(Includes 1,680 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.7 min

New Construction

Structures:

• Culverts > 36”: 19
• Tunnel: Yes
• Bridges: 4

Length Within Parks: 3.2 miles

Construction Footprint: 245 acres

Construction Schedule: 3 years

Watershed Crossings

Wilson Creek: 6

Mill Creek: 3

Estimated Construction Cost in 2016 $ (Millions)

$798M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 200 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The Project stakeholders and the project development team agreed in late 2018 to eliminate the three C alternatives from further study for the following reasons:

1. The Expert Risk Assessment estimated that these alternatives have a high risk of geotechnical failure. The risk of building these alignments is higher than staying on the current alignment and making improvements as alternative X would do.
2. The C alternatives have no unique environmental benefits.
3. The C alternatives are high cost and have high environmental impacts.



(Includes 1,680 foot tunnel)

Travel Time Added (minutes)

Added Time: 1.5 min

New Construction

Construction Length: 8.6 miles

Structures:

• Culverts > 36”: 14
• Tunnel: Yes
• Bridges: 5

Length Within Parks: 4.0 miles

Construction Footprint: 265 acres

Construction Schedule: 4 years

Watershed Crossings

Wilson Creek: 6

Mill Creek: 4

Estimated Construction Cost in 2016 $ (Millions)

$848M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 200 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The Project stakeholders and the project development team agreed in late 2018 to eliminate the three C alternatives from further study for the following reasons:

1. The Expert Risk Assessment estimated that these alternatives have a high risk of geotechnical failure. The risk of building these alignments is higher than staying on the current alignment and making improvements as alternative X would do.
2. The C alternatives have no unique environmental benefits.
3. The C alternatives are high cost and have high environmental impacts.



(Includes 1,680 foot tunnel)

Travel Time Added (minutes)

Added Time: 2.6 min

New Construction

Construction Length: 11.7 miles

Structures:

• Culverts > 36”: 21
• Tunnel: Yes
• Bridges: 11

Length Within Parks: 7.0 miles

Construction Footprint: 330 acres

Construction Schedule: 4 years

Watershed Crossings

Wilson Creek: 6

Mill Creek: 10

Estimated Construction Cost in 2016 $ (Millions)

$1,003M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 216 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.2 min

New Construction

Length: 8.4 mi

Footprint: 262 acres

Schedule: 3 years

Cost (in Millions)

Minimum: $770M

Maximum: $900M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 216 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.0 min

New Construction

Length: 9.3 mi

Footprint: 282 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $840M

Maximum: $980M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 216 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 2.0 min

New Construction

Length: 12.5 mi

Footprint: 344 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,130M

Maximum: $1,320M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 228 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 4.1 min

New Construction

Length: 11.4 mi

Footprint: 299 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,020M

Maximum: $1,200M

Existing Habitat Type

Coastal scrub/grassland /spruce: 0 acres

Riparian: 22 acres

Clear cut: 0 acres

Young Redwood Forest: 254 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 3.9 min

New Construction

Length: 12.2 mi

Footprint: 319 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,100M

Maximum: $1,280M

Existing Habitat Type

Coastal scrub/grassland /spruce: 0 acres

Riparian: 22 acres

Clear cut: 0 acres

Young Redwood Forest: 254 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion included geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For the Feasibility Study, the primary impacts to avoid were natural resources and cultural landscape. An essential question answered in this process was whether an alternative provided a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 5.0 min

New Construction

Length: 15.5 mi

Footprint: 381 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,390M

Maximum: $1,620M

Existing Habitat Type

Coastal scrub/grassland /spruce: 0 acres

Riparian: 22 acres

Clear cut: 2 acres

Young Redwood Forest: 264 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres

(Includes 2,425 foot tunnel)

Travel Time Added (minutes)

Added Time: 0.8 min

New Construction

Construction Length: 3.0 miles

Structures:

• Walls: Unknown
• Tunnel: 1
• Bridges: 1

Length Within Parks: 1.7 miles

Construction Footprint: 53 acres

Construction Schedule: 4 years

Watershed Crossings

Wilson Creek: 1

Estimated Construction Cost in 2019 $ (Millions)

$672M

Existing Habitat Type

Coastal scrub/grassland /spruce: 21 acre

Riparian: 1 acre

Clear cut: 2 acres

Young Redwood Forest: 27 acres

Mature Redwood Forest: 3 acres

Old Growth Redwood Forest: 1 acre

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment and the dark pink segment with yellow border indicates the approximate position of the tunnel.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

Travel Time Added (minutes)

Added Time: 0.8 min

New Construction

Construction Length: 3.1 miles

Structures:

• Walls: Unknown
• Tunnel: No
• Bridges: 2

Length Within Parks: 0.9 miles

Construction Footprint: 56 acres

Construction Schedule: 3 years

Watershed Crossings

Wilson Creek: 2

Estimated Construction Cost in 2019 $ (Millions)

$300M

Existing Habitat Type

Coastal scrub/grassland /spruce: 22 acres

Riparian: 1 acre

Clear cut: 3 acres

Young Redwood Forest: 28 acres

Mature Redwood Forest: 3 acres

Old Growth Redwood Forest: 3 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

Travel Time Added (minutes)

Added Time: 2.2 min

New Construction

Construction Length: 2.2 miles

Structures:

• Walls > 1
• Tunnel: No
• Bridges: No

Length Within Parks: 2.2 miles

Construction Footprint: 47 acres

Construction Schedule: 3.5 years

Watershed Crossings

Wilson Creek: N/A

Estimated Construction Cost in 2019 $ (Millions)

$300M

Existing Habitat Type

Coastal scrub/grassland /spruce: 28 acres

Riparian: 0 acres

Clear cut: 0 acres

Young Redwood Forest: 0 acres

Mature Redwood Forest: 18 acres

Old Growth Redwood Forest: 1 acre

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current LCG alignment.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal, and mitigation.

What is Alternative X?

Alternative X includes a large-scale subsurface drainage system and additional retaining structures to reduce impacts to the roadway due to landslide movement. The highway alignment would generally follow the current highway’s alignment with one travel lane in each direction and eight-foot shoulders.

Alternative X would include:

• Minor realignment retreat to the east at key locations;
• Drainage infrastructure to reduce landslide movement; and
• Steel-reinforced timber-lagged retaining walls.

Alternative X is the lowest cost build alternative, would have the smallest environmental footprint of all the alternatives studied to date, and would have the shortest construction duration. The anticipated time to construct Alternative X is approximately 3-5 years and the current estimated cost to construct it is $880 million (in year 2031 dollars).

On the map, the alternative is denoted with a letter. The red line indicates the current LCG alignment.

Please note the following:

• The lines on the map are approximate and do not indicate the exact placement of the alternative.
• Costs are estimated and include construction, materials disposal, and mitigation.