Galactic radial metallicity and [α/Fe] gradients traced by open clusters. Top: cluster [M/H] values as a function of their Galactocentric distance R. Clusters are marked by circles colour coded according to their age. The grey shaded areas represent the 68% and 95% confidence intervals of the linear models resulting from the Bayesian regression, while the black dashed line traces the most probable model. Bottom: Cluster [α/Fe] values as a function of their Galactocentric distance R. Symbol colours and shaded areas are the same as those in the top panel.