Impact Analysis

Conveyal Analysis helps you evaluate changes to your public transportation system using accessibility indicators, measures of what transit riders can access in a given amount of time. For example, the proportion of the job market that is reachable in less than 45 minutes of walking and transit.

Although planners have emphasized the importance of accessibility concepts for years, conventional planning often employs measures of mobility, focusing on the speed and throughput of vehicles as an end in itself. But in a high-density area, even if movement is slow, many nearby destinations can be reached. Planning should focus on providing residents with access to opportunities and amenities.

With Conveyal Analysis you can easily create multiple transportation scenarios, measuring and comparing the accessibility impact of different investments. You can focus on changes at individual locations, interactively visualizing the accessible area (isochrones) and the number of opportunities reachable as travel time increases. The analysis can then be expanded to the regional level, with similar indicators calculated at every point throughout the region.

Combine transit with walking, biking, and driving

The Conveyal Analysis network model includes stop locations and timetables for every transit line, 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. A transit stop on the other side of a river is not necessarily usable. 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 multi-modal 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. Depending on the timetable, several infrequent lines running along the same street may or may not provide waiting times much lower than half of the headway.

You can specify a particular percentile of travel time for your accessibility indicator. For example, someone going to the grocery store may be satisfied with a median travel time of 30 minutes, but someone traveling to a job with an inflexible schedule may require a transportation option that always takes less than 45 minutes.

You may know the planned frequency of routes added or changed in scenarios, but not their complete timetables. In this case, travel time and accessibility results will contain uncertainty that Conveyal Analysis can visualize and account for when comparing results.

Conventional traffic models often use large zones representing entire districts, which may then be treated as a single point. Travel times can vary significantly across these zones. Conveyal Analysis works with high resolution regular grids to eliminate these concerns.

Rapid Turnaround

With Conveyal Analysis, you can draft 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, Conveyal Analysis 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, removing, and modifying transit lines. It is possible to edit frequencies, alignments, and speeds. This web-based platform doesn't require any software to be installed.

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 Conveyal Analysis completes jobs that would require hours or days on a single workstation in minutes using a cluster of hundreds of computers.

Open Source, open data formats

Conveyal Analysis uses open data sources and standards like GTFS and OpenStreetMap, and its source code is published under the permissive, open source MIT 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.