Just about every major highway in Southern California has a plan to improve. The largest of those is the widening of the I-405 Freeway, slated to begin this Friday, Jan. 26.

Here’s a look at the big road projects that are underway or proposed.

A snapshot of projects

*On express lanes, motorists can enter if they have the required number of passengers, or pay.

I-405 improvement plan

At an estimated $1.9 billion, the I-405 improvement plan is the largest to begin construction in 2018 in California. Groundbreaking on the project is Jan. 26. Commuters will begin to notice construction beginning this spring, continuing through 2023.

The plan calls for 18 bridge replacements plus new and widened bridges. Five bridges will be closed to traffic at times during construction.

The I-405 today

The average daily traffic for I-405 from Bolsa Avenue to Westminster Avenue is about 282,000 vehicles. The average daily traffic at the I-405/22 interchange is more than 300,000 vehicles.

New lanes to be added:

Work zone safety

Do not tailgate. You need at least 2.5 seconds to react and one second for every 10 mph you are traveling. If you are traveling at 55 mph, you need at least eight seconds to stop.

Fines are doubled in highway work zones. They can easily top $1,000 for drivers who speed, drive aggressively, text, or are distracted driving through a work zone.

Eighty-five percent of those killed in a work zone are drivers and/or passengers, not workers.

In 2013, 45 percent of California highway work zones had at least one crash.

185 Caltrans workers have been killed on the job since 1921.

A work-zone crash occurred once every 5.4 minutes in the U.S. in 2015.

Major Projects in Orange County

Location: I-405 from I-605 near the LA County line to SR-73 in Costa Mesa (16 miles)

Project description: The project includes adding one regular lane in each direction between Euclid Street and I-605 and making improvements to freeway entrances, exits and bridges. In addition, the project will add the 405 Express Lanes, incorporating the existing carpool lanes and a new lane in each direction between SR-73 and I-605. The 405 Express Lanes will give solo drivers the choice to speed up their commute for a toll and give options for carpoolers to use the lanes for free. When the express lanes open, two-person carpools will pay a toll only during peak hours and carpools of three or more will be free at all times.

Construction period: 2018-2023

Total project cost: $1.9 billion

Location: I-5 Widening Project from El Toro Road, south to SR-73

Project description: This project will take place in 3 segments and will add one general purpose lane in both the northbound and southbound directions from Avery Parkway to Alicia Parkway, extend the second carpool lane in each direction from Alicia Parkway to El Toro Road, reconstruct the Avery Parkway and La Paz Road interchanges, construct new auxiliary lanes at 6 locations and reestablish auxiliary lanes, modify on-ramps and off-ramps at 6 locations, convert buffer separated carpool lanes to continuous access, provide standard lane and shoulder widths throughout the majority of the project limits

Construction period: 2019-2023

Total project cost: Approximately $550 million

Location: SR-55 Widening Project

Project description: Add new general purpose and HOV lanes in each direction and add additional auxiliary lanes from I-405 to I-5 near Tustin

Construction period: 2021 – 2025

Total project cost: Approximately $410 million

Location: I-5 South County Improvement Project (Avenida Pico to San Juan Creek Road)

Project description: This 5.7-mile project extends from Avenida Pico in San Clemente to San Juan Creek Road in San Juan Capistrano. The four-year, $230 million project will: Add a carpool lane in both directions on I-5 from Avenida Pico to San Juan Creek Road; Improve the sight distance on the southbound curve north of PCH; Reconstruct the interchange at Avenida Pico, including widening the northbound Avenida Pico on-ramp to three lanes, and providing dual left-turn lanes to both on-ramps; and add sound walls where needed.

Construction period: 2014-2018

Total project cost: $230 million

Location: I-5 (SR-57 to SR-55)

Project description: Add second carpool lane in each direction in the cities of Santa Ana, Orange and Tustin

Construction period: 2018-2020

Total project cost: $40 million

Location: SR-22 (Eastbound Route 22 from Harbor Boulevard to northbound 5/57 Interchange.)

Project description: Improve and reconfigure Connector

Construction period: Late 2018

Total project cost: $10 M

Major Projects in Los Angeles

Location: I-710 – Port of Long Beach

Project description: Gerald Desmond Bridge Replacement

Construction period: 2012-2021

Total project cost: $1.2 billion

Location: I-5 (SR-14 Connector to Parker Road)

Project description: Construct HOV and Truck Lanes

Construction period: 2019-2021

Total project cost: $440 million

Location: I-5 (Olive Avenue in Burbank to Sheldon St./Laurel Canyon Blvd. in LA)

Project description: Widen and realign highway for HOV lanes, realign Metrolink railroad tracks

Construction period: 2012-2022

Total project cost: $402.4 million

Location: I-5 (Orange County line to Olive Avenue in Burbank)

Project description: Widen and realign highway for HOV, general purpose lanes, rehab pavement

Construction period: 2016-2022

Total project cost: $3.2 Billion

Location: I-5 (SR-14 Connector to Lake Hughes Road in Castaic)

Project description: Roadway rehabilitation

Construction period: 2017-2019

Total project cost: $171 million

Location: 101 (Liberty Canyon Road, Agoura Hills)

Project description: Wildlife Habitat Connectivity

Construction period: TBD

Total project cost: TBD

Location: I-10 Puente Avenue to SR-57

Project description: HOV Lanes

Construction period: 2014-2021

Total project cost: $343 million

Location: 71 (SR-60 interchange to I-10)

Project description: Upgrade route from 4 lane expressway to 8 lane highway

Construction period: 2020-2023

Total project cost: $243 million

Location: LA-057 (SR-57 connector to Golden Springs Drive)

Location: 71 (SR-60 interchange to I-10)

Project description: Reconstruct SR-57 connector to SR-60; construct eastbound SR-60 bypass off-ramp to Grand Avenue; construct southbound Grand Avenue to eastbound SRr-60 loop on-ramp.

Construction period: 2020-2024

Total project cost: $263 million

Location: LA-605-Carson Boulevard to Telegraph Road

Location: 71 (SR-60 interchange to I-10)

Project description: Road rehabilitation.

Construction period: 2022-2025

Total project cost: $81.5 million

Location: LA-060-I-710 to I-605

Location: 71 (SR-60 interchange to I-10)

Project description: Pavement rehabilitation.

Construction period: 2018-2020

Total project cost: $75 million

Location: LA-405-Western Avenue to Crenshaw Boulevard

Location: 71 (SR-60 interchange to I-10)

Project description: Construct auxiliary lane, road widening, ramp improvements.

Construction period: 2020-2023

Total project cost: $68 million

Location: LA-047-Port of LA

Location: 71 (SR-60 interchange to I-10)

Project description: Schulyer Heim Bridge Replacement

Construction period: 2011-2020

Total project cost: $247 million

Location: LA 60 (I-710 to County Line)

Location: 71 (SR-60 interchange to I-10)

Project description: Bridge freight corridor improvement.

Construction period: 2021-2024

Total project cost: $38.6 million

Major Projects in Riverside/San Bernardino

Location: Riverside Mid-County Parkway between I-215 and SR-79 near Ramona Expressway; I-215 between Nuevo Road and Van Buren Boulevard.

Project description: Being held up due to funding and litigation

Construction period: Begins mid-2019

Total project cost: $1.35 billion

Location: I-10 near Coachella from east of Coachella Canal to Desert Center

Project description: Rehabilitate mainline pavement, shoulders and ramps

Construction period: 2022-2026

Total project cost: $157 million

Location: I-10 in Beaumont and Banning from I-10/SR 60 to I-10/SR-111

Project description: Replace pavement on the two outside lanes and outside shoulders.

Construction period: Late 2018 to Mid-2022

Total project cost: $188.5 million

Location: I-10 in and near Coachella from east of Coachella Canal to Desert Center

Location: Rehabilitate mainline pavement, shoulders and ramps

Construction period: Late 2022 to Early 2026

Total project cost: $157 million

Location: I-10 near Blythe from SR 177 to Teed Ditch

Location: Rehabilitate mainline pavement, shoulders and ramps

Construction period: Late 2020 to Early 2024

Total project cost: $263 M

Location: I-10 near Blythe from Teed Ditch to Arizona State Line

Project description: Rehabilitate mainline pavement, shoulders and ramps

Construction period: Late 2022 to Early 2026

Total project cost: $207 M

Location: I-15 in Lake Elsinore from SR-74 to Cajalco Road in Corona

Project description: Express Lane Project – Southern Extension (RCTC Lead Agency)

Construction period: In Planning Phase for 2023

Total project cost: $544 million

Location: I-15 in Corona from Cajalco Road to SR-60

Project description: Construct Express Lanes (RCTC Lead Agency)

Construction period: 2018 to 2020

Total project cost: $403.5 million

Location: SR 60 Riv Near Beaumont from Gilman Springs to Jack Rabbit Trail

Project description: Construct truck climbing lane

Construction period: Late 2018 to Mid-2021

Total project cost: $121 million

Location: SR-79 from Domenigoni Parkway to Gilman Springs Rd

Project description: Realign to 4-lane highway (RCTC Lead Agency)

Construction period: Mid-2020 to Early 2023

Total project cost: $1.07 billion

Location: SR-91 from Main Street to I-15

Project description: Construct Express Lane North Direction Connector (RCTC Lead Agency)

Construction period: Mid-2020 to Late 2022

Total project cost: $180 million

Location: I-10 SBd from LA County Line to Cherry Avenue (Phase 1)

Location: Widen to two express lanes each direction (SBCTA Lead Agency)

Construction period: Mid-2018 to 2022

Total project cost: $457 million

Location: I-10 SBd In Ontario between Grove Avenue and 4th Street

Project description: Construct partial interchange, remove 4th Street interchange and widen 4th Street (Lead Agency City of Ontario)

Construction period: Mid-2020 to mid-2022

Total project cost: $236 million

Location: I-15 in Riverside County from .3 miles south of Cantu-Galleano Ranch Road to 1.2 miles north of Duncan Canyon Road in San Bernardino Coutty

Project description: Two express lanes in each direction from SR-60 to SR-210; one express lane in each direction from Cantu-Galleano Ranch Road to SR-60 and from SR-210 to Duncan Canyon Road and one auxiliary lane in each direction between SR-60 and I-10 and northbound between 4th Street and Miller Avenue (SBCTA Lead Agency)

Construction period: Mid 2021 to Mid-2024

Total project cost: $330 million

Location: I-15 in Hesperia and Victorville from Ranchero Road to .4 miles north of Mojave Drive overcrossing

Project description: Rehabilitate existing mainline and ramp pavement.

Construction period: Late 2020 to mid-2023

Total project cost: $137 million

Location: SR-58 from .4 miles west of Kern County line to 7.5 miles east of USR-395 (Kramer)

Project description: Construct 4-lane divided expressway; SR-58/USR-395 interchange and railroad bridge.

Construction period: Early 2018 to Late 2020

Total project cost: $191 million

Location: SR-60 in Ontario from Euclid Avenue interchange to Riverside County line and near Riverside from San Bernardino County line to Country Village Road and from .7 miles west of Valley way to 60/91/215 interchange

Project description: Replacement of two outside lanes and concrete slabs.

Construction period: Late 2018 to Mid-2021

Total project cost: $131 million

Location: SR-210 in Highland and Redlands from Highland Avenue to San Bernardino Avenue

Project description: Add one mixed flow lane in each direction, widen shoulders and median and improve Baseline Rd. interchange (SBCTA Lead Agency)

Construction period: Late 2019 to Late 2021

Total project cost: $146 million

Sources: Caltrans, OCTA, SBTA, Metro.net, U.S. Department of Transportation

Photo: Caltrans