Transportation authorities are increasingly recognizing the crucial role that transit and non-motorized transportation modes play in the performance of the transportation system. Advanced modeling tools, such as activity-based travel demand models, dynamic traffic assignment and schedule-based transit assignment models are the most promising approach to support planning decisions in complex, multi-modal networks. While these tools can model transportation systems more realistically, and provide various set of network performance and user data in the most disaggregate way, interpreting their results may still be a challenging task. As an example, in a schedule-based transit assignment, measures can be calculated for each vehicle, route, stop, etc. Moreover, network-level analyses such as corridor travel time, accessibility and connectivity, origin-destination analysis, and select link analysis are among the common analysis using the dynamic network models.

There are multiple ways in which modeling outputs and data can be combined and analyzed, and different temporal and spatial aggregation schemes may be preferred depending on the needs of specific applications. We propose a web-based framework to visualize transit modeling results and data in order to increase the value and usability of advanced modeling tools. This tool is based on a graph representation of the transit system consistent with the roadway network, which makes possible multi-modal analyses. It can also present passenger-based results, going beyond the capabilities of tools which only consider GTFS data. While our framework may be used to visualize GTFS, its main focus is on facilitating the use and interpretation of modeling result for planning purposes, as well as to make model calibration and validation easier. The visualization tool is web-based developed in Python in the back end and JavaScript in the front end. It connects with a Mongo database where model outputs are stored. It also takes advantage of open-source data, i.e., OpenStreetMap (OSM) and General Transit Feed Specification (GTFS). The visualization tool has the following characteristics:

• Web-based: A password-protected website hosts the tool with data residing on a server with parallel computing features. It makes it faster and accessible to wide range of users.

• Open Source: It uses the open source technologies, and based the visualization on open data such as OSM and GTFS.

• Interactive: It gives the users the flexibility of querying and visualizing various aspect of the system.

• Flexible Data Aggregation: It gives the option to look at different aggregation schemes, and make customized query.

• Animation: Portrays the evolution of network performance in time in a time-dependent network.

The application of the framework for visualizing the FAST-TrIPs transit assignment model results is presented. It includes the visualization of: route level performance measures such as ridership, load factor and service reliability for specific transit vehicle or a set of vehicles in a given time interval, stop-level measures such as boarding and alighting passengers and vehicles dwell time, and path flow/attractiveness for a selected set of origins and destinations.