Large scale urban planning consultations can elicit public contributions with limited reflectivity and scope in comparison with participatory projects in HCI. We therefore investigated how digital technology can be configured to enable participation at greater depth and at scale in Metro Futures 2020an online public consultation on light rail trains. Drawing on participatory methods used in HCI, we devised experience-centered and creative activities at different depths and scales from "shallow and wide" social media polls to "deep and narrow" online workshopsand a website with three ways of exploring a digital train mock-up. Participation on the website was both at scale and to notable depth according to our analyses of data entry behavior and website comments. Our findings show that the value of online public consultations can be increased through providing experiential context for design proposals, supporting exploration of design details via immersion, and providing interconnected activities of varying depths and scales.