Drivers complain of bumpy rides on Friendship Bridge after resurfacing

Drivers have complained about a noticeably bumpy ride on Friendship Bridge following the resurfacing of its approach sections, prompting Legislative Assembly member Leong Hong Sai to visit the site and provide a technical analysis of the issue.

The bridge is currently undergoing large-scale maintenance work, which began in mid- to late May on the southern and northern approach sections.

The project, expected to be completed by mid-August at the earliest, focuses on resurfacing the roadway and replacing expansion joints.

While some approach sections have already been resurfaced, many motorists have reported that vehicles feel unstable and that the road surface seems “softer” and more uneven than before.

Some have questioned whether the problem lies with the new asphalt material or the quality of the paving work, according to the Macao Daily News.

Engineer and Legislative Assembly member Leong Hong Sai visited the site and analyzed the situation, citing design constraints, drainage requirements and material property contrasts as key factors.

He pointed out that the approach sections of the bridge, which opened in 1994, feature expansion joints installed every 12 meters – a structural design choice dating back more than three decades.

At normal driving speeds of 37 to 50 mph (60 to 80 kilometers per hour), vehicle tires pass over an expansion joint every 0.5 seconds.

This high-density succession of impacts inherently produces a “bouncing” effect, which he described as a characteristic of the bridge’s design.

Drainage slopes create wavy appearance

Leong also noted that the bumpy sensation is most pronounced in the slow lane, where motorcycles predominantly travel, while the fast lane is relatively smoother.

According to the bridge’s original design, drainage outlets are placed at the midpoint between every two expansion joints in the slow lane.

To prevent motorcycles from losing traction during Macau’s rainy season, the asphalt pavement must slope downward from the expansion joints toward the drains at a gradient of approximately 0.4% to 0.5%.

Over a distance of just six meters, this slope inevitably produces minor geometric undulations.

Leong further explained that expansion joints are rigid structures made of steel and concrete, while the newly laid pavement consists of flexible asphalt concrete.

The sharp contrast in material stiffness means that when vehicles pass over the junction between the two, the “rigid versus soft” interface creates slight dynamic rebound forces at higher speeds, amplifying the perceived roughness.

He emphasized that while driving comfort is important, “life safety must be the primary consideration” in engineering decisions, particularly when balancing smooth rides against safe drainage during heavy rain.

Temporary protruding peaks

Regarding reports of particularly pronounced bumpiness on certain sections, such as the slow lane from Taipa toward Macau, Leong said this is due to a construction transition period.

Asphalt resurfacing on those sections has been completed, but the full replacement of expansion joints has not yet begun, leaving rigid “protruding peaks” at the joint locations.

He said this is a temporary condition and that once the new expansion joints are fully installed and leveled, the driving experience is expected to improve.

Leong did not rule out the possibility of construction-related issues, such as height inconsistencies between expansion devices and the road surface.

He said that if such problems exist, they would be identified during the acceptance inspection process, and remedial measures could still be taken if unacceptable bumpiness is detected.

25 years since last major resurfacing

The current maintenance work comes 25 years after Friendship Bridge’s last major resurfacing in 2001.

Authorities had previously noted that the asphalt layer had suffered severe wear and tear and that potholes often appeared at expansion joints on the approach sections after rainfall, creating safety hazards.

The project involves resurfacing the approach roadways with PG100 modified asphalt, repainting traffic markings, replacing existing GTF expansion joints with polyurethane alternatives and upgrading traffic signposts.

A second phase of maintenance work on the main bridge and bridge towers is also being planned, with data collection and a preliminary proposal currently underway.

Traffic remains heavy despite diversion

Even after the opening of the Macao Bridge, which has diverted some traffic, Friendship Bridge continues to carry tens of thousands of vehicles daily.

According to official data, the bridge recorded an average daily traffic volume of 56,947 vehicles last year.

In the decade before the Macao Bridge opened, daily traffic typically ranged from 60,000 to 70,000 vehicles, underscoring the bridge’s role as a vital cross-sea artery connecting the Macau Peninsula with the outlying islands.