Pan Island Expressway

The PIE was initially conceived by the Public Works Department as part of plans to expand Singapore's road network in the 1960s, to cope with a predicted large rise in traffic volume over the next two decades.[3] It was the result of a four-year planning study conducted in 1967 by the Singapore government with foreign planning consultants, and which was funded by the United Nations Development Programme.[4]

Intended to connect Singapore's satellite towns and industrial estates, it was to act as the main connector between different parts of Singapore, and be able to cope with high traffic volumes.[5]

Construction of the PIE started in 1964 and took place in four phases.[6] Jalan Toa Payoh, a 2 miles (3.2 km) segment of the expressway between Thomson Road and Woodsville Circus, was completed by June 1969,[5] and the segment between Woodsville Circus and Jalan Eunos, named Jalan Kolan Ayer and Paya Lebar Way, was completed by 1970.[7] Work on the 8 miles (13 km) section between Jalan Anak Bukit and Thomson Road began in March 1970, and was estimated to cost $2 million.[8] During the construction of this section of the expressway, rocks had to be blasted near Adam Road,[9] and Kampong Chantek Bahru, off Bukit Timah Road, was cleared to make way for the expressway.[10]

In January 1975, the section of the expressway between Jalan Eunos and Kallang Bahru was completed, and Jalan Kolam Bahru, between Kallang Bahru and Woodsville Circus, was improved to form part of the expressway.[11] The section between Adam Road and Jalan Anak Bukit was opened in October 1976,[12] and construction of the eastern part of the PIE, between Jalan Eunos and Changi Airport, commenced in 1976.[13]

Work to expand Whitley Road to three lanes in each direction, along with the construction of a grade-separated interchange to link it with the PIE, commenced in November 1977.[14] The section of the expressway between Adam Road and Whitley Road was completed by 1978, and was opened to traffic in 1979. Work on the PIE between Jalan Anak Bukit and Boon Lay Road also commenced in 1978.[15] To connect this section to the rest of the PIE, a $15.2 million viaduct over Jalan Anak Bukit and Upper Bukit Timah Road was constructed.[7]

On 10 January 1981, the 10 kilometres (6.2 mi) segment of the PIE between Jalan Eunos and the East Coast Parkway was officially opened by Mr Teh Cheang Wan, the then-Minister for National Development, having cost $50 million to construct.[16] The section of the expressway between Upper Bukit Timah and Corporation Road was opened soon after, on 31 January 1981, by Mr Lee Yiok Seng, then the Parlimentary Secretary (National Development).[17] With the completion of two flyovers, across Aljunied Road and Paya Lebar Road, in June 1982, three months ahead of schedule, the PIE was fully opened.[18]

Upon its opening, the PIE was noted to have had a positive impact on traffic flow in certain areas, alleviating traffic, as was reported in a preliminary PWD study in October 1981.[19]

The Pan Island Expressway (PIE) is being extended and realigned from Jurong Camp to Pioneer Road North. The extension and realignment are part of an 8-km extension from Hong Kah Circle to Upper Jurong Road at Safti, since 2 October 1991. The Public Works Department is also undertaking an extension from Hong Kah Flyover to Tuas. Modification and extension of the western end of the expressway started on 1 October 1991 to connect it to the Kranji Expressway which was being built at that time. A new 8 kilometres (5.0 mi) section was built. It forked from the existing PIE at Hong Kah Flyover, intersecting the Kranji Expressway at Tengah Flyover and ending at the Tuas Flyover with the Ayer Rajah Expressway. It replaces some roads - Hong Kah Circle, Lorong Kabong, Bulim Cemetery, Gek Poh Road and Joo Tiong Road. The 2 kilometres (1.2 mi) section of the old PIE from Hong Kah Flyover to Corporation Road was downgraded to an arterial road and renamed Jurong West Avenue 2. On 3 December 1993, the PIE extension was opened from Jurong Road all the way to Upper Jurong Road, and converting parts of Upper Jurong Road into Pan Island Expressway.

As the amount of traffic using the KJE and PIE to Jurong Industrial Estate increased, the Land Transport Authority upgraded the stretch of the PIE between Tengah Flyover and Tuas Road to a four-lane dual carriageway from a three-lane dual carriageway. The work started in March 2004 and ended in March 2006.[20]

Beginning in July 2011, the stretch of the PIE between Clementi Avenue 6 and Adam Road was widened. The widening work involved adding one lane to both sides of the expressway as well as the structural expansion of the existing Eng Neo, Chantek and Anak Bukit Flyovers. The widened portions were progressively opened to traffic from July 2013.[21]