function d = compute_PI_control(d,t)
    
    for i = 1:d.p.K_b
        
        if t == 1
            % It is the first time step; previous value of v(i,t)
            % does not exist. Choose v(i,t) = v_max_traffic(i,t)
            
            d.s.v(i,t) = d.s.v_max_traffic(i,t);
            
        else
            
            %% WRITE YOUR CODE HERE
            d.s.v(i,t) = ...
            
        end
        
    end
    
end