Impact Analysis

Conveyal Analysis helps you evaluate changes to public transport systems using accessibility indicators. These indicators quantify the access to opportunities experienced by transit riders, such as the proportion of the regional job market reachable within 45 minutes of total walking and transit time.

Although planners have emphasized the importance of multimodal accessibility indicators for years, conventional practice often employs isolated mobility measures that prioritize vehicle speed and throughput. But mobility is means to an end; even if movement is slow in a dense area, many destinations may be nearby and within reach. Planning should focus on providing people with access to opportunities and amenities, and indicators for evaluating impact should reflect this focus.

With Conveyal Analysis you can easily create multiple transportation scenarios, measuring and comparing the impact of different investments in terms of accessibility. You can focus on changes at a specific location, interactively visualizing the accessible area (isochrones) and number of opportunities reachable from that location as a travel time limit increases.

Comparing isochrones and distributions of workforce accessibility for two scenarios

Comparing isochrones and distributions of workforce accessibility for two scenarios

Results can then be expanded to the regional level, with similar indicators calculated for every point of a high-resolution grid. Weighting these regional analyses by different categories of residents and households can help you assess the equity impacts of different scenarios. Comparing scenarios at a regional level can give you insights into the wider benefits of transit investment, highlighting locations that may see unexpected gains in access thanks to network effects.

Region-wide workforce accessibility results

Region-wide workforce accessibility results


Combine transit with walking, biking, and driving

The Conveyal Analysis network model automatically includes stop locations and timetables for transit lines in your region’s GTFS feeds, as well as a complete street network that distinguishes foot paths, bike paths, and various classes of mixed-traffic streets.

The street model accounts for the fact that walking, biking, or driving may not be possible, or may require a lengthy detour. Some types of roads and paths are only accessible to certain modes of travel (a bike path for example), and vehicles travel at different speeds on different types of roads.

In addition to transit, walking, biking, and driving, Conveyal Analysis models a wide range of multimodal travel options including park-and-ride lots, with bike sharing support on the way.


Rigorous, Detailed Modeling

Transit travel and waiting times can vary greatly depending on the exact time of departure. Conveyal Analysis captures this variation, considering rider experience at all times within a user-specified time range.

Timetables allow us to properly measure waiting and transfer times and the effects of multiple complementary routes to a destination. For example, a scenario may include a timed transfer between two infrequent lines, providing a short wait time independent of headway. Similarly, overlapping routes in a corridor may lower waiting times for passengers, depending on exact timetables.  

You may know the planned frequency of routes added or changed in scenarios, but not specific, detailed timetables. In this case, travel time and accessibility results will contain uncertainty that Conveyal Analysis can visualize and account for when comparing results.  Other modeling tools that rely on effective headways often have difficulty representing such scenarios accurately.

To reflect behavioral differences in departure time flexibility for various trip purposes, Conveyal Analysis allows you to specify a particular percentile of travel time for your accessibility indicator. Someone going to a grocery store may be satisfied with a median travel time of 30 minutes, but people traveling to work with inflexible schedules may require trips that almost always (say, 95% of the time) take less than 45 minutes, even if they cannot adjust their trip start to match transit schedules.


Rapid-Turnaround Scenario Planning

Conveyal Analysis allows you to edit a transportation scenario and see the results quickly enough to evaluate new ideas during a meeting.

For regions with transit data in the GTFS format and good OpenStreetMap coverage, you can create a network model automatically in a matter of minutes. Our map-based scenario editor is specifically designed for editing public transportation networks. It allows adding and removing routes, as well as modifying their frequencies, alignments, dwell times, and speeds.

Add Route


The travel time and accessibility characteristics of scenarios can be visualized immediately. Results for a single location are available in an interactive isochrone view in a matter of seconds. Detailed analyses of entire regions require thousands of times more calculation, but our cloud-based Analysis platform completes jobs that would require hours or days on a single workstation in minutes using cutting-edge computing clusters.  The web-based Analysis interface does not require any software to be installed on your computer other than a web browser.

Additional modules allow you to publish scenarios to public-facing, interactive websites that can communicate the accessibility benefits of scenarios in public outreach.


Open Source, open data formats

Conveyal Analysis uses open data sources and standards like GTFS and OpenStreetMap, and its source code is published and freely downloadable under an open-source license. We believe that open data and open licenses have an important role to play in planning and policy work, ensuring reproducibility of results and transparency of public decision processes, as well as reusability of software created through public sector investment. We are constantly developing new features and analysis capabilities, and our commitment to open software fosters the potential for wider public benefit from this work.



We can provide access to our cloud-hosted Analysis platform for partners and agencies of all sizes.  We also offer consulting services for custom analysis projects, research, and new features to meet your needs.