When downloading OpenRoads Designer, the latest release (10.02.00.60) only shows Size = 1MB, where previous builds were greater than 1000MB.
Beginning with the 10.02 release, OpenRoads Designer CONNECT Edition is now delivered with a new on-demand installer. While some core application files are included in the initial installation download, most of the other application files are download as need during the installation based on what is already installed on your computer and what options you select during the installations. The OpenRoads Designer on-demand installer includes all the available OpenRoads Designer regional datasets, companion features and the companion application LumenRT (if selected). This installer respects all the traditional installer options, such as silent and administrative deployment.
If you are concerned about slow internet connection or excessive download times, you may want to consider creating a deployment image as discussed in his article: https://communities.bentley.com/products/road___site_design/w/road_and_site_design__wiki/33575/silent-installdeployment-image-for-openroads-designer-connect-edition