The checks are part of Delhi’s curbs, in force since November 1, on vehicles that don’t meet the prescribed emission standards. You are using an outdated browser. Please upgrade your browser to improve your experience and security. While GRAP II was imposed in Delhi on Monday as the air quality turned 'very poor', border checks to implement the bar on non-BS VI vehicles gridlocked Delhi-Meerut Expressway and NH9 at UP Gate.