The main purpose of this study is to measure environmental effects and recreational benefits under different hypothetical scenarios program, involving quality improvement in Tien‐Wei Highway Garden, which is the biggest cultivated flower land in Taiwan. The contingent behavior model was adopted. The data combined actual number of trips under current quality of environment combined and the intended number of trips for expected scenarios of environmental quality improvement and congestion mitigation. For the empirical model, on‐site Poisson model was performed to correct truncated and endogenous stratification issues from on‐site surveys. The results show that the estimated average consumer surplus is greater in contingent behavior method than the one in the traditional travel cost model. Also, the estimated recreational benefits in contingent behavior method are more precise than those in the traditional travel cost method. The environment benefits to consumers are communicated with the programs that changes in environment quality. Meanwhile, the incremental economic benefits comprise the gain associated with the improvement of environmental quality.