Modifying link capacity to avoid Braess Paradox considering elastic demand

A common practice to improve travel efficiency is to expand the existing road infrastructure; however, as pointed out by Braess Paradox, this expansion may worsen congestion. Braess Paradox has been extensively studied, but very few have touched on the governance of the paradox links. As such, this research aims to detect the effects of closing and expanding a paradox link and to find effective measures for avoiding Braess Paradox. The results identify two types of paradox links: non-monotonic and monotonic. For monotonic links, higher capacity worsens Braess Paradox even if the link capacity is increased to an unlimited level, whereas, for non-monotonic, it is possible to avoid Braess Paradox by modifying link capacity. Finally, the results also show that persistent expansion would not lead to a massive improvement in travel efficiency and that the expansion is not always helpful. • Three measures are studied for avoiding Braess Paradox in elastic demand profile. • B algorithm is extended for traffic assignment problems under elastic demand. • The numerical example is executed in three real-life motorway networks. • Higher capacity may worsen Braess Paradox even if it increases to an unlimited level.