The SDEIS preferred alternative removed the existing viaduct and set I-70 below grade. A large cover over the highway provided space for a public park to help connect the neighborhoods. Numerous street and rail crossings spanned the depressed highway. The model was the primary tool used to easily communicate the complex multi-level design concept to the public.
The model included all the residential, commercial and industrial properties within one block of either side of I-70, the complete highway system of four interchanges, three overpasses and the cover, two rail crossings, and two pedestrian crossings.
When the model was being completed the project was in the concept design phase so POITRA had to rely on the Colorado M&S Standards publication in order to add the proper pavement markings essential for realism.”
M.P., POITRA Visual
Visual Simulations Project Manager
Since the public needed to quickly recognize the locations within the model a fairly high level of detail was called for. POITRA included fencing, retaining walls, soundwalls, curbs, traffic signals, soundwalls, barriers, walks, islands, medians, traffic, pavement markings and vegitation.
POITRA modelers laid out the project from concept level plans. Profile grades of I-70 and the interchange ramps as well as connections to cross streets had to be carefully managed to ensure that all vertical clearences were correct and the roadway surfaces met up as designed. Changes to the design during construction of the model were cause for major concerns.
The Dahlia Street Interchange marks the end of the subgrade segment of I-70. In fact the I-70 profile emerges from the subgrade to climb up and over Dahlia Street. It is the final interchange in the POITRA model.
Once the model was completed POITRA modelers rendered a large series still views for each major node: interchanges and overcrossings. A series of animations were also rendered for each node which included moving traffic. The animations were created in High Definition (HD) and at a 15 Frames Per Second (FPS) a standard frame rate for web publication.
POITRA created an interactive tour of the model on the I-70 East EIS public website using a 3D map navigation system for each node that include still views and animations chosen to best describe the project.
The model tour was published just prior to the SDEIS public hearings.