By making use of the paradox that expanding the road network may not be able to improve the benefit of the whole network and travellers,the complexities of transportation problems and the effectiveness of the two economic approaches to solve traffic congestion were analysed.The principles of travellers’ routing selection were introduced by using Braess paradox.The influence of the variation of total traffic demand on network equilibrium states of Braess paradox was analysed.Lovell paradox with multiple OD pairs and its features were presented.Based on Lovell paradox,the application effects of traffic congestion pricing and tradable bottleneck permits were analysed.The results show that the variation of total traffic demand has a direct influence on network equilibrium states.There still exists the paradox that expanding network results in no any improvement of benefit of traffic network with multiple OD pairs.Congestion pricing implemented easily achieves its expected result hardly,but tradable bottleneck permits implemented costly may achieve a good result.