Department of Transportation

The “Roosevelt Road and Keelung Road Intersection Traffic Safety Improvement Project” prioritizes traffic safety. Based on international literature, on-site observations, and discussions at the expert review committee, the orthogonal intersection design has been confirmed to provide greater safety benefits than standard lane marking improvements, with an estimated accident reduction of over 60%. Bus-only lanes will also be retained to maintain optimal public transportation efficiency. Regarding the proposed improvements to road markings, after reviewing international literature and conducting on-site observations of actual traffic flow at the Gongguan Roundabout, the potential accident reduction from modifying road markings is estimated at about 5–12%, which is rather limited. In contrast, the orthogonal intersection design is estimated to have a 63% potential for improvement. This conclusion has also been confirmed through expert review and finalized in committee discussions.

As for the reason for filling in the bus-exclusive underpass, the roundabout requires a hollowed-out central island. Retaining the hollow section would require vehicles to pass over it, which demands sufficient structural strength. Preserving the underpass would necessitate capping the central island and constructing foundation piles on both sides of the roadway, with an estimated construction period of about two years. This approach would occupy two inner lanes of the roundabout, causing significant traffic disruption. Furthermore, only three lanes would remain at surface level, one of which is for left turns, leaving insufficient capacity for through traffic. By contrast, filling in the underpass requires an estimated construction period of about two months, with a smaller work zone and relatively minor traffic impact. It also allows additional road space to add another lane, effectively improving traffic flow at the surface-level intersection.

Bus-only lanes will be maintained but converted to surface-level lanes. With coordinated traffic signals at upstream and downstream intersections, simulations show that about 60% of buses will no longer need to stop at signals, while those that do will clear the intersection within a single signal cycle. Through buses on Roosevelt Road will remain on dedicated bus lanes, avoiding mixing with general traffic. Left-turning buses from Keelung Road to Roosevelt Road can directly enter the bus-only lane, reducing conflicts with general traffic—similar to the approaches on Ren’ai Road or Xinyi Road—ensuring priority for public transport.

This improvement plan has been repeatedly discussed with experts, scholars, and community groups, and presented to local stakeholders. After integrating all feedback, the orthogonal intersection design remains the optimal solution. Future improvements will continue to prioritize safety as the primary consideration.

2025-08-28