Heavy fog and low visibility added to the usual rush hour on Tuesday with forecasters urging motorists to drive carefully. Fog was reported in Zayed City in Abu Dhabi, Al Minhad area in Dubai, around Sharjah and routes heading towards Ras Al Khaimah. Several cars collided on Sheikh Zayed Road causing delays into Dubai near Jebel Ali. Earlier, a bus fire in Dubai Marina also caused delays this morning. There was bumper-to-bumper traffic on Al Ittihad Road from Al Nahda area in Sharjah heading to Dubai. Heavy delays were reported on Al Ribat Street nearby Mirdif and on Mohammed bin Zayed Road from the Sharjah Ring Road towards Muhaisanah. Similar conditions were reported on on Ras Al Khor Road heading towards Dubai. Commuters heading to Dubai on the Dubai-Al Ain Road after Zayed University experienced heavy traffic. Traffic build-up was also reported from Wafi Mall towards Dubai World Trade Centre. In the capital, congestion delayed early commuters with traffic at a standstill on Al Bateen Street and on Dhafeer Street near Sheikh Zayed bin Sultan Street.