P-Turn Safety on Sarawak’s Pan Borneo Highway: Enhancing accessibility while mitigating risks

By Ir. Meheron Selowara Joo

A P-Turn on Sarawak’s Pan Borneo Highway

The implementation of P-Turn facilities along Sarawak’s Pan Borneo Highway presents a critical challenge in road safety – balancing the need for seamless accessibility with the risks associated with high-speed travel on a partially access-controlled highway.

According to Ir. Meheron Selowara Joo, Chair of Curtin Highway Infrastructure Research and Innovation Hub (CHIRI), while the Pan Borneo Highway upgrade marks a significant improvement in connectivity, it also introduces new safety concerns.

“The transition from a lower-tier R3 single-lane road to an R5 dual-carriageway highway is a major leap in infrastructure, but it comes with operational complexities,” said Meheron, who is also a Senior Lecturer in Civil and Construction Engineering at Curtin Malaysia.

He credited the Sarawak government, the Public Works Department (JKR), and federal agencies for successfully delivering the upgrade while navigating the challenges of partial access control – a key consideration in rural highway design that seeks to maintain mobility for local communities.

Unlike fully access-controlled highways such as the PLUS Highway in Peninsular Malaysia, where entry and exit points are strictly designated, the Pan Borneo Highway allows for more flexible access. While this benefits local residents by reducing travel distances, it also increases exposure to fast-moving traffic.

Ir. Meheron Selowara Joo

 

 

Managing Higher Operating Speeds

 One of the main safety challenges, Meheron noted, is the natural increase in vehicle speeds due to the improved road conditions. While the posted speed limit is 90 km/h, actual travel speeds often exceed this, increasing the risk of collisions – especially for motorists entering or exiting the highway.

“Residents using the Pan Borneo Highway must remain highly vigilant. The enhanced road quality leads to higher operating speeds, which can pose significant risks if drivers do not adhere to proper safety measures,” he warned.

P-Turns: A Necessary Yet Risk-Prone Solution

 Designed to facilitate safer crossings, P-Turns serve as an alternative to conventional U-turns on high-speed, median-divided highways. The Pan Borneo Highway is set to feature over 200 P-Turns, strategically positioned based on traffic impact studies, particularly in areas with high population density.

“The primary advantage of a P-Turn is that it allows vehicles to accelerate within an acceleration lane before merging with highway traffic, reducing conflict with faster-moving vehicles,” Meheron explained. “However, the effectiveness of P-Turns hinges on strict adherence to safety guidelines.”

Key Risks Associated with P-Turns

While P-Turns are a viable solution for managing access on high-speed highways, Meheron outlined several safety risks:

  • Illegal U-turns – Some motorists take shortcuts by ignoring the full P-Turn manoeuvre, increasing the likelihood of collisions.
  • Limited night-time visibility – Poor lighting at P-Turns can make it difficult for drivers to accurately judge the speed of oncoming vehicles.
  • Unsafe lane changes – Vehicles switching lanes abruptly to commence a P-Turn can disrupt traffic flow.
  • Speeding violations – The improved road design encourages higher travel speeds, making it harder for merging vehicles to enter safely.
  • Poorly located P-Turns – Sight distances can be limited, particularly at crests and curves, making it harder for drivers to anticipate merging traffic. Additional warning signage is crucial at such locations.
  • Illegal parking at P-Turn facilities – Parked vehicles obstruct visibility and disrupt the intended traffic flow.

The Path Forward: Strengthening Safety Measures

Despite these risks, Meheron affirmed that P-Turns remain an appropriate solution for partially access-controlled highways, provided road users and enforcement agencies work together to uphold safety standards. “Enforcement, awareness, and infrastructure improvements must go hand in hand,” he stressed.

“A collaborative approach is essential to ensure that the Pan Borneo Highway remains both efficient and safe for Sarawak’s communities.”