Can I use gray LEGO® pre-school train tracks with the older black DUPLO® tracks?

Yes, both kinds of LEGO DUPLO track pieces can be combined. We recommend alternating the two types of tracks though because the black tracks are a little lower and their surface isn't grooved to prevent slipping. That's why it's best not to use black tracks near the bridge, too. They also have different lengths and different distances between points.