Maken, who was out of the city, said that effect of the experiment cannot be measured in short term as various factors contribute to it.
"Presently, there is an extended weekend in Delhi. Traffic on roads is thin and schools are closed. A large number of people are out of the city on new year," the Congress leader said.
"As an idea to control pollution in the city, we do not oppose the odd-even formula. But it needs to be implemented with adequate planning," he added.