The Tallah bridge will be closed to traffic from the night of January 4 to make way for the dismantling of the 57-year-old structure, which engineers have said is no longer fit to bear vehicular load.

Police are apprehensive that after the Tallah bridge is shut to traffic, BT Road could be struggling to accommodate the additional vehicular load. Since September 28, heavy vehicles were banned from taking the bridge and an elaborate diversion plan was drawn up for buses, minibuses and other vehicles.

Lalbazar has now warned that those using small vehicles to reach Shyambazar from the north — such as Dunlop, Sodepur or Barrackpore — will possibly have to suffer long snarls during rush hours, particularly in the morning.

At a recent meeting of senior police officers from three police commissionerates — Barrackpore, Howrah and Bidhannagar — Lalbazar has drawn up a diversion plan for those travelling by small vehicles along BT Road to reach Shyambazar or further south.

Metro lists the options that have been proposed.

• Small vehicles coming from far away Naihati and Barrackpore and headed towards Calcutta may reach Sodepur and then take a left turn on to Sodepur Road and reach Jessore Road from Madhyamgram and then keep moving towards the airport
• Cars and other small vehicles coming from north can reach the Dunlop intersection, take a left turn on to PWD Road and then access Belghoria Expressway to reach Jessore Road and the airport
• Small vehicles from Baranagar can avoid BT Road and instead take Gopal Lal Thakur Road that runs parallel to BT Road and head straight to reach Cossipore Road down Chitpore
• Some of the smaller vehicles from Sinthee More can reach Chiria More, take a right turn to reach Khagen Chatterjee Road and then reach Cossipore Road to move towards Bagbazar
• At Chiria More, small vehicles can take a left turn on to Dum Dum Road and then reach Belgachhia down Northern Avenue before turning right to reach Shyambazar through the Belgachhia bridge
• Small vehicles from Howrah and Serampore that would otherwise reach Dunlop and then take BT Road to reach Shyambazar will be advised to take Kona Expressway and the second Hooghly Bridge to Calcutta
• Heavy vehicles that leave parts of Burrabazar and Posta at night to reach Barrackpore or even further north will have to take Strand Road, the second Hooghly bridge and Kona Expressway to reach Dunlop.