The status of activity on which a person has spent relatively longer time of the preceding 365 days prior to the date of survey is considered to be the usual principal activity status of the person.The Usual Principal Activity status (UPS), written as Usual Status (PS), is determined using the majority time criterion and refers to the activity status on which h/she spent longer part of the year. Principal usual activity status is further used to classify him in/out the labour force. For instance, if an individual was 'working' and/or was 'seeking or available for work' for major part of the year preceding the date of survey then h/she is considered as being part of the 'Labour Force'. For example if an individual reports as having worked and sought/available for work for seven months during the year or having sought or available for work for seven months then h/she is classified as being in the Labour Force.

• The Bogibeel bridge spans the River Brahmaputra between Dibrugarh and Dhemaji districts of Assam and is India's longest rail-road bridge
• Dhola-Sadiya bridge built over river Lohit, a tributary of River Brahmaputra, links Dhola in Assam to Sadiya in Arunachal Pradesh and is India's longest river bridge (9.15 km long)