Factoring in traffic congestion and environmental degradation in Delhi, researchers have pitched for exploring a sustainable multimodal transport system with high accessibility and said with greater access to the metro network, people would prefer it as the "main mode" for travel via MMTS. The researchers in a study titled "GIS and Gravity Model-Based Accessibility Measure for Delhi Metro", published recently in a foreign journal, have also claimed that the implementation of the phase-IV project of the Delhi Metro "could reduce the average travel time between zones and metro stations".