Traffic volume count has been collected on a $2$-lane road section which needs upgradation due to severe traffic flow condition. Maximum service flow rate per lane is observed as $1280\:veh/h$ at level of service ‘C’. The Peak Hour Factor is reported as $0.78125$. Historical traffic volume count provides Annual Average Daily Traffic as $12270\:veh/day$. Directional split of the traffic flow is observed to be $60:40$. Assuming that traffic stream consists of ‘All Cars’ and all drivers are ‘Regular Commuters’, the number of extra lane(s) (round off to the next higher integer) to be provided, is ______.