The objective of this paper is to prove the effectiveness of variable message sign information on recurrent congestion using different measurements of effectiveness. To show the benefits of the information systems, we have built a new methodology. We took advantage of the data collected during a national strike which shut down the variable message signs. By comparing these data to a set of 'normal' days we can evaluate the impact of information systems on congestion level. We present a way to measure the effectiveness of information systems. For the evaluation of information effectiveness we use both qualitative and quantitative measurements. This allows us to finally give a financial assessment of information systems for commuters. Our study is based on an 80 km long suburban network in Lyon. We show that the benefits of an information system can be evaluated between 0.7 and 1 M per year (between 0.9 and 1.3 M US $ per year).