Rethinking Elevated Expressway: A global perspective

Shafiqul Alam Is elevated expressway accessible to all? No, the elevated corridors are only for the purpose of enabling cars, two wheelers, three wheelers and highway buses to some extent to move at a high speed and not for facilitating the movement of public transport. Again, unplanned land uses may lead to acute congestion on approach roads and there could be disastrous consequences in the event of accidents or breakdowns. Critics often suggest elevated expressway, roadway capacity expansion, bus improvements, road pricing or some type of mobility management programme to address traffic congestion. However, what is worse, elevated expressway and roadway expansion can reduce traffic congestion only in the short run but this benefit tends to decline over time due to generated traffic, and the additional vehicle travel tends to increase other costs such as downstream traffic congestion and parking demand, total accidents, energy consumption and pollution emissions. Advocates generally exaggerate the benefits and underestimate the full costs of highway expansion. Cities all over the world are replacing elevated expressways with surface streets, saving billions of dollars on transportation infrastructure and giving greater emphasis on mass transport. A number of American expressways have been demolished or are in the process of restoration. These are Alaskan Way Viaduct, Sheridan Expressway, the Skyway and Route 5, Route 34 New Haven, Claiborne Expressway New Orleans, Interstate 81, Route 29, Gardiner Expressway, and 11th Street Bridges and the Southeast Freeway. Some other freeways have also been demolished in the United States, such as, the Central Freeway; Embarcadero Freeway, San Francisco; and Central Artery, Boston. Cheonggye Expressway in South korea also came under demolition. The Central Freeway, opened in 1959, was damaged by the Loma Prieta Earthquake in 1989 and a segment was subsequently demolished and in 1999, with both freeway retrofit and removal initiatives appearing on the ballot, voters approved the removal of the freeway and the replacement boulevard. The Hayes Valley segment of the freeway was closed for good in 2003. Of the half-dozen points observed three experienced decreases in traffic, while none experienced increases greater than 10 per cent. While Embarcadero Freeway in San Francisco completed in 1959, a double-deck elevated highway, resulting in a physical and visual barrier between downtown and the waterfront. At its peak, the Embarcadero Freeway carried more than 60,000 cars per day. It was torn down shortly after the 1989 Loma Prieta Earthquakes and finally closed. As of 2000, traffic on the Embarcadero was approximately 26,000 vehicles per day, or less than half that on the old freeway. While post-closure counts indicate that remaining traffic was displaced onto alternative routes to and from the Bay Bridge, it appears to have been successfully absorbed, as levels of service were not substantially degraded. Boston's "Big Dig" project was one of the most ambitious freeway replacement projects in the world, creating an underground freeway to replace the elevated Central Artery that sliced through the heart of downtown Boston. Built over 5 years at a cost of approximately $ 5.0 billion, the project exceeded its original budget by a factor of five. While few would find the Big Dig an example to be followed, Boston did replace the full capacity of its elevated freeway with an underground facility and reclaimed the land that the freeway displaced. Cheonggye ("clear valley stream") is a former seasonal waterway in the city center of Seoul, South Korea. The stream was covered and replaced by the Cheonggye Road and Cheonggye Elevated Highway. Prior to demolition, combined traffic counts on both roads were approximately 168,000 vehicles per day, about five eighths of which was through-traffic. While before and after traffic counts for the corridor were unavailable, the number of vehicles passing through downtown decreased by 9 per cent. Summer temperatures in the park, according to project planner Kee Yeon Hwang, are 7.0 degrees (F) lower than at locations a quarter- mile away. Finally, in 2004 the city's bus system was fundamentally restructured. Most significantly, a network of median bus-only lanes introduced in 1996 was greatly expanded: by 2005, four routes extended 22 miles, by 2007, the system had reached seven routes and 42 miles, and by 2010, it should encompass 2 routes and 73 miles. The result: within months, rider satisfaction had reached 90 per cent. In the light of the above, whether elevated expressways or toll-ways are effective in alleviating gridlocks is a matter of rethinking. It is better to rethink before spending millions of dollars. So, time has come to think out of the box that means in a way other than conventional way. The writer can be reached at email: shafiqul0032@yahoo.com