The metro pillar work began on Monday near Bengaluru's Devarabeesanahalli flyover on the Outer Ring Road (ORR) and traffic congestion is likely to occur for next few days, the Bengaluru Traffic Police said. Traffic movement from Kaadubeesanahalli to DB Halli will be slow and pillar work might take a while to complete, the Hindustan Aeronautics Limited (HAL) traffic police said.