The numbering can be confusing because the projects are essentially successive pieces of a much larger southern Luzon expressway network.

Coverage: Alabang, Muntinlupa
Length: 1.2 km

TR1 involved the rehabilitation, widening and upgrading of the Alabang Viaduct. It helped modernise the southern gateway of the SLEX system.

Coverage: Filinvest, Muntinlupa → Sta. Rosa → Calamba, Laguna
Length: 27.3 km

TR2 expanded the existing SLEX corridor, including widening sections between Filinvest, Sta. Rosa and Calamba.

Coverage: Calamba, Laguna → Sto. Tomas, Batangas
Length: 7.6 km

TR3 is particularly important because it extended SLEX into Batangas and connected it with the Southern Tagalog Arterial Road (STAR Tollway).

In simple terms: Metro Manila → SLEX → Calamba → Sto. Tomas

That is where the existing expressway effectively ends.

This is the missing link. The project extends SLEX from Sto. Tomas, Batangas through Laguna and Quezon to Lucena.

The SLEX system is controlled by San Miguel Corp. (SMC) through its infrastructure subsidiaries.

For the existing SLEX/TR1-TR4 concession, SMC SLEX Inc. is the concessionaire/investor, while Manila Toll Expressway Systems Inc. (MATES) operates and maintains the toll road.

The government, through the Toll Regulatory Board, awarded the concession in 2006.

For TR5, the project is being undertaken through a joint venture involving San Miguel Holdings Corp. and Philippine National Construction Corp. (PNCC).

A Supplemental Toll Operations Agreement was signed in June 2022.

The original SLEX concession awarded in 2006 runs for 30 years, ending in 2036.

TR5, meanwhile, was structured as a 30-year Build-Operate-Transfer (BOT) concession.

That means these are not simply government-built roads. Private concessionaires finance, develop and operate the infrastructure for a defined period, recovering their investment through toll revenues under the terms approved by the government.

The importance of TR4 goes far beyond shaving minutes off a road trip. The mainland Luzon itself is a long and huge island: With an area of 109,965 sq km, the island is roughly3.2 times larger than the entire Netherlands.

For decades, motorists using the existing Maharlika Highway/Asian Highway 26 corridor from Manila have had to pass through towns and urbanised areas of Laguna and Quezon.

Local traffic, buses, trucks, last-mile rides/tricycles, roadside commerce, intersections and narrow sections can turn relatively short distances into hours-long journeys.

TR4 creates a controlled-access alternative.

That means through traffic — particularly long-distance passenger and freight traffic — can bypass many of the congested sections.

The project is expected to attract around 17,000 vehicles a day, according to the latest government-related reporting.

The economic significance could be even greater.

A faster road means shorter delivery times, lower vehicle operating costs, more reliable logistics, easier movement of products, stronger tourism links, and new commercial development.

And TR4 is only half of the larger vision. Once TR4 reaches Lucena, it provides the launching point for TR5 toward Bicol.

In effect, the long-term plan is: Metro Manila toMatnog ni Sorsogon, thus creating a substantially more continuous expressway spine along southern Luzon.

TR4 has an unusually long history.

The concept dates back decades, with former President Benigno Aquino III saying in 2015 that the idea could be traced to the Marcos administration and had subsequently gone through government approval processes. The project finally broke ground in 2019.

It was originally expected to be completed much earlier, but right-of-way acquisition and other implementation problems repeatedly delayed construction.

SMC itself has identified right-of-way (ROW) acquisition as one of the principal challenges of a project of this scale.

That history makes the latest December target particularly significant — but also means motorists have reason to remain cautious about treating the target as a guaranteed full opening.

The key development in 2026: DoTr officials are no longer talking only about completion of the entire TR4; they are targeting a partial opening.

Packages A, B and C — effectively Sto. Tomas to Tiaong — are scheduled to become operational by December. That would attack one of the most notorious congestion points on the southern route first.

The remaining packages toward Candelaria, Tayabas and Lucena will follow.

And once TR4 is eventually completed, the bigger prize is even more consequential: a continuous high-speed road from Metro Manila deep into Quezon — and eventually, through TR5, toward Bicol and Matnog.

For commuters and motorists, the benefit is measured in hours saved.

For businesses, it is measured in logistics costs and delivery reliability.

For Quezon and Bicol, it could mean greater access to markets, ports, tourism destinations and investment.

And for the Philippine road network, TR4 and TR5 represent something more ambitious: the gradual transformation of the southern Luzon corridor from a long, congested highway journey into a connected expressway spine stretching from Metro Manila toward the Bicol peninsula.