The government claims that the newly built Delhi–Jaipur Expressway will cut vehicular emissions by 35 percent by reducing traffic congestion and promoting fuel efficiency. Independent researchers, however, argue that improved roads often trigger “induced demand,” leading to higher traffic volume and overall emissions. They also point to poor maintenance and lack of electric-vehicle infrastructure as limiting factors. The long-term ecological balance, they say, depends more on transport behaviour than on road design alone. Which of the following, if true, most seriously weakens the government’s claim about emission reduction due to the expressway?