South Luzon Expressway

South Luzon Expressway (left) and Skyway (right) near Villamor Airbase at the Pasay–Taguig boundary

From Magallanes Interchange in Makati, Osmeña Highway becomes also known as Skyway At-Grade. At the southbound lanes, it is intersected by two streets towards Magallanes Village. Past the Sales Interchange at the city boundary of Pasay and Taguig, it becomes a toll road where expressway restrictions begin to be enforced. From there, it includes service roads on either side up to Alabang. Parallel to the highway, the PNR Metro South Commuter Line also runs between the at-grade and elevated Skyway segments until it passes the C-5 Exit. The Nichols toll plazas, which has two toll barriers on each direction, and a southbound exit towards Merville, Parañaque could then be found. Past C-5, the two expressways follow the same alignment as it enters Parañaque, one running above the other. They slightly curve and pass over Bicutan before running in a straight line, past the Sucat Exit and Dr. Santos Avenue, until they reach the Alabang Viaduct. The highway continues its straight line southward as it enters Muntinlupa, passing over barangays Sucat, Buli, and Cupang, before approaching Alabang, while the elevated Skyway curves westward and descends toward Alabang-Zapote Road. Alabang Exit was the terminus of the Osmeña Highway from 1969 to 1976, before the Alabang Viaduct was built and the expressway extended to Calamba. It is also the site of the former Alabang Toll Barrier prior to the split of the entire SLEX into two concessions, namely the Skyway System and SLTC-SLEX (formerly PNCC-SLEX). It climbs over the National Highway (National Road or officially Manila South Road) through the Alabang Viaduct, before it descends and becomes the Alabang-Calamba-Santo Tomas Expressway (ACTEx) or SLEX Main.

SLEX Main, South Luzon Tollway (SLT), and Alabang–Calamba–Santo Tomas Expressway (ACTEX) are the alternate names for the part of the R-3 held by South Luzon Tollway Corporation. The ACTEX name refers to the segment of the two SLEX concessions from Alabang Exit in Muntinlupa up to Santo Tomas Exit in Santo Tomas, Batangas.

South Luzon Expressway in Carmona

SLEX Main/ACTEX starts past Filinvest Exit (Exit 23), with two to four lanes per direction and mostly paralleling the four-lane National Highway over Muntinlupa and northwestern Laguna.[3] The road slightly curves over barangays Bayanan and Putatan on Muntinlupa. Also located between Filinvest and Susana Heights Exits are the future southern ends of Skyway Extension, currently under construction.[4] The expressway's first service area, Tollway Plaza, having a Shell gas station, and several restaurants such as Jollibee, KFC, Greenwich, Burger King, among others, is also located at this segment. Past that service area, South Luzon Expressway mostly follows a straight course, passing the interchange serving Muntinlupa–Cavite Expressway, Susana Heights Subdivision, the National Highway, and barangays Poblacion and Tunasan in Muntinlupa.

It soon enters Laguna at San Pedro, continuing as a straight roadway lined with billboards and passing through the city's residential and industrial areas before curving and ascending past the Petron and Caltex service areas to clear San Vicente Road, the disused spur of the PNR South Main Line towards General Mariano Alvarez, Cavite, and Pacita Avenue. South Luzon Expressway soon enters Biñan, passing near Southwoods City, Barangay San Francisco (Halang), and Splash Island, before entering Carmona, Cavite. It passes through Carmona in about one kilometer, with an exit to serve the town proper, before re-entering Biñan at Santo Tomas Bridge. The first route marker for AH26 is found at this segment. Returning to Biñan, the road runs straight over barangays Santo Tomas (Calabuso) and Mamplasan, with an exit to serve the Laguna International Industrial Park, several residential communities such as Brentville and Jubilation, and the Cavite–Laguna Expressway. A Caltex service area is on the southbound lane past Mamplasan. It soon crosses the Silang-Santa Rosa River and enters Santa Rosa, Laguna on a straight route, mostly lined with trees. It intersects Santa Rosa–Tagaytay Road to Santa Rosa city proper and Tagaytay through a partial cloverleaf interchange. South Luzon Expressway reduces into 3 lanes, having guard rails as the median divider. The road passes near Enchanted Kingdom, the Univation Motor Philippines Inc. factory (formerly of Nissan Motor Philippines), and Eton City and is within the limits of barangays Pulong Santa Cruz and Malitlit. A Total service area lies on the northbound lanes of the expressway.

South Luzon Expressway enters Cabuyao, passing near Malayan Colleges Laguna (formerly the location of the warehouses owned by the defunct Uniwide Sales Inc.) and Santa Elena Golf and Country Club. It crosses the San Cristobal River and enters Calamba, going in a straight route until the Calamba Exit. South of the river, two Petron service stations could be found on opposite sides of the road. The road then approaches the Calamba toll plaza, widening to 18 lanes (including the lanes on the second southbound toll plaza and the northbound lanes), before returning to 3 lanes per direction. It passes through barangays Mayapa, Batino, and Prinza before approaching Calamba Exit. At the Calamba Exit, the Pan-Philippine Highway concurrency ends as it leaves the expressway towards the west as Maharlika Highway. Calamba Exit was the former terminus of the South Luzon Expressway from 1976 to 2010, when the expressway was extended to connect with STAR Tollway and bypass the congested Maharlika Highway over Turbina.

Calamba–Santo Tomas segment of SLEX looking south towards STAR Tollway

Past Calamba Exit, the expressway narrows to 2 lanes per direction without exits. It follows a curved route paralleling the Pan-Philippine Highway (Maharlika Highway) from Calamba to Santo Tomas, Batangas. It clears another disused spur of the PNR South Main Line towards Batangas City, approaches the Ayala Greenfield Estate toll plaza, continues over barangays Saimsim and Makiling, and then enters Batangas on Siam-siam Bridge. A few meters north of the Laguna–Batangas border is the location where the future Toll Road 4 will branch off. The expressway then curves and clears the same disused PNR spur to Batangas City before it ends at kilometer 57.2, continuing toward Batangas City as the STAR Tollway. However, the kilometer count of the next expressway after the Santo Tomas exit starts at kilometer 60.

From kilometer 28.387 at San Pedro, Laguna southwards,[2] the Dr. Jose P. Rizal Highway segment runs through the province of Laguna, as well as a segment of Carmona at Cavite province before continuing back to Laguna from Biñan towards the exit at Calamba through the Maharlika Highway. The highway was also part of the Osmeña Highway until 1992, when R.A. 6760 was amended, which named the segment after the Philippine national hero and Laguna native, Dr. José Rizal.[2] The road starting from Alabang Viaduct in Muntinlupa up to Santo Tomas, Batangas forms the South Luzon Tollway, handled by the South Luzon Tollway Corporation, a joint venture of the Philippine National Construction Corporation and the SMC-backed Citra group of Indonesia.[5]

SLEX Calamba segment in 2007, prior to the completion of rehabilitation work

Prior to rehabilitation, the South Luzon Expressway was mostly an expressway with a grass median and 2 lanes per direction from Alabang to Calamba. Rehabilitation work started in 2006, with heavy traffic brought by construction work. Alabang Viaduct was widened to 4 lanes per direction, and the construction of Skyway Stage 2 caused traffic disruptions on the Bicutan-Alabang segment (though mitigated by the use of the sosrobahu method to build and position the bridge piers). Rehabilitation work was finished in 2009, and the Alabang-Calamba segment was expanded to 3 to 4 lanes.

In 2010, an extension of the expressway, named Alabang–Calamba–Santo Tomas Expressway or ACTEX was opened, eventually connecting South Luzon Expressway to the STAR Tollway.

The SLEX Toll Road 4, also referred to as Toll Road 4 (or simply TR4), is a 66.74-kilometer (41.47 mi)[8] extension of South Luzon Expressway from Calamba (near its boundary with Santo Tomas, Batangas) to Lucena. Construction will be divided into five segments, with one additional extension to Mayao in Lucena on the revised project outline.[9][10] The extension project is implemented by the Toll Regulatory Board and will be operated by the South Luzon Tollway Corporation (SLTC). The extension would decongest the existing national road between Santo Tomas and Lucena, and provide a modern alternate route for travellers from Quezon to the Bicol Region. Right of way has been acquired for the first three segments between Santo Tomas and Tiaong, and ongoing for the remainder between Tiaong, Candelaria, and Tayabas. Right of way acquisition is ongoing as of 2019, and the groundbreaking ceremony was held on March 26, 2019, alongside the beginning of construction.[11] The future expressway will start near the Ayala Greenfield Estate toll plaza in Calamba rather than in Santo Tomas after various project alignment revisions due to right-of-way issues.

The SLEX Toll Road 5, will be the extension of South Luzon Expressway to Matnog, Sorsogon from Lucena. The total length of the extension would be 420 kilometers (260 mi). The extension hopes to decongest Andaya Highway and Pan-Philippine Highway, cut travel time from Manila to Naga by 2 to 3 hours, and to Matnog by 6 hours, and soon to be built by Manila Toll Expressway Systems Inc., a company partly owned (40%) by the Philippine National Construction Corporation, the rest shared equally by the local firm Alloy Manila Expressway Inc. and the SMC-backed Citra Group of Indonesia which bought the shares formerly owned by the MTD Capital Berhad of Malaysia. On June 29, 2020, The Toll Regulatory Board issued a resolution to declare this project a Toll Road upon the request of, and based on the proposal submitted by the joint venture (JV) of the Philippine National Construction Corporation (PNCC) and San Miguel Holdings Corporation (SMHC).[12] On August 25, 2020, San Miguel Corporation thru SLTC announced they will invest this project alongside the Pasig River Expressway with a cost of ₱122 billion in order to boost economy in the Luzon Island.[13]

Other planned expansion projects in the SMC-PNCC joint venture pipeline with connections to either SLEx and the Skyway system include:[14]

Caltex service area in Mamplasan, Biñan, Laguna

The South Luzon Expressway currently has 8 service areas, with 4 on each direction. Most of the service areas occupy large land areas and have restaurants and retail space, with the exception of two service areas between Cabuyao and Silangan Exits, which are simply Petron gas stations, both opened in 2016, with no other shops other than a San Mig Food Ave convenience store and car repair services. The service areas also provide ETC reloading for Autosweep RFID users. Although there is a Shell gas station located along Skyway At-Grade southbound in Magallanes, Makati, it is uncertain if it is officially considered as a service station despite having restaurants and a Shell Select convenience store as it is located on the toll-free segment.

The South Luzon Expressway also has lay-bys, or emergency parking areas where motorists can stop for safety checks on their vehicles and other emergencies.