MSV Software

Model | Measure | Monitor

Mobility simulation and visualization, with special focus on safety

Mobility Simulation and Visualization (MSV) is a 3D microscopic traffic simulation software designed to identify safety vulnerabilities in traffic layouts by simulating vehicle and pedestrian movements. Supporting both lane-based and space-based behavior, MSV enables realistic modeling of diverse traffic conditions. It adopts a pathway-and-stream-based approach instead of traditional network modeling, allowing the testing of unconventional movements and complex junctions, particularly in scenarios like disaster response or event management. Users can define control mechanisms such as priority rules or signals to regulate flows, while the software identifies near-miss and incident-prone spots, facilitating layout modifications and comparative performance analysis.

In addition to standard performance metrics like travel time and stopped time, MSV models bus stops, taxi stops, toll booths, and similar facilities to study queuing effects and benefits. Built using Unity3D, MSV offers tools to draw shapes, import images, and annotate layouts with traffic signs, creating visually intuitive simulations. It provides detailed output statistics and empowers traffic engineers, planners, and researchers to optimize layouts and control strategies. MSV also serves as a valuable educational tool for students.

(The picture above shows a vulnerable spot where a natural collision occurs in a suburban area in Surat, India.)

Features

Way

In MSV, a ‘way’ refers to a physical space or path that vehicles can use, which is not necessarily a road. Vehicles move in streams composed of a collection of ways created over a map, blueprint, or image. This flexibility allows for the creation of vehicle movements in any desired direction, including those that are neither explicitly permitted nor restricted but may obstruct regular traffic flows. Without the use of ways, modeling such scenarios—common in chaotic traffic environments—would be significantly more challenging with a traditional node-link setup. For instance, see the model snapshot of a typical uncontrolled junction on the outskirts of Chennai. The white arrow marks indicate flows in allowed directions. However, it is noteworthy that people often exploit gaps in the road to make crisscross movements (depicted by yellow arrows) or even travel against the flow of traffic (red arrows). Such behavior is common at uncontrolled intersections, which are prevalent in towns and cities of developing countries. Including this in modeling is crucial for enabling a more in-depth assessment of safety issues.

Stream

A stream represents the path taken by a set of vehicles traveling from the start to the end points of their journey. In MSV, a stream is defined as a sequence of ‘Way’ objects. A stream does not necessarily use all lanes of each Way it traverses; instead, it can utilize one or more lanes from each Way included in its path. Streams can overlap, sharing whole or partial segments of a Way beneath them. Each stream is assigned a flow value and modal split percentages. The snapshot illustrates a junction at Purdue University (USA), with three streams originating from the south and diverging toward the west, north, and east directions, sharing one or more lanes of the underlying Way. In compact areas, such as single or dual-junction study zones, defining streams enables a more realistic representation of lane changes compared to traditional node-link setups. In conventional modeling, vehicles often lack sufficient space for proper lane changes, resulting in unrealistic behavior such as transitioning from one incorrect lane to another within the junction. Streams effectively resolve constraint.

Behavior

Chaotic traffic behavior can occur when lane discipline is not followed, or when lane-following is unnecessary. In fact, some roads do not require lane markings. The reason for this is not a lack of discipline but the presence of diverse vehicle shapes and speeds. When vehicle dimensions vary significantly, traditional car-following and lane-changing behaviors, such as queuing, cannot be expected. Smaller vehicles naturally occupy the spaces between larger ones. To address this, MSV employs a new space-based vehicle-projection logic, which will be explained further. Instead of relying on nodes, links, and the traditional methods of describing a network, MSV uses streams of vehicles on predefined paths, enabling the modeling of small areas with exceptionally high fidelity. This approach is not limited to chaotic traffic; lane-based regular traffic operations can also be modeled using the same logic. This allows for the utilization of novel outputs, such as identifying near-miss spots and locations with a high likelihood of accidents, enhancing the overall utility of the simulation.

Control strategies

When two or more streams intersect, they form a conflict area. MSV offers both priority control and signal control options to manage these intersections. Priority control allows users to specify high-priority and low-priority streams, similar to major-minor road categorizations or the application of yield signs. A single junction can have multiple priority control areas to accurately represent the control operations. For signal control, users can define the operation using data such as the number of phases, the durations for green, yellow, and red lights, and the streams allowed to proceed during each phase. If multiple junctions share the same timing configurations, a single controller can manage all of them, significantly reducing modeling time. Free-left (or free-right) turns can be incorporated into both priority and signal control setups. Additionally, pedestrian phases can be seamlessly integrated into the signal operation, ensuring comprehensive and realistic traffic management modeling. Where necessary, priority control can be combined with signal control to model more realistic traffic management operations.

Detailed Outputs

The primary simulation outcome in MSV is the identification of vulnerable spots for near misses and incidents within the layout. Detailed information, such as which vehicle was about to collide with another, along with the location and time of the event, is collected and included in the statistical output. Users can modify the layout, test improvements, and compare results before and after adjustments. Traditional performance indicators, such as travel time and stopped time, are also provided for basic layout performance evaluation. Study-area-level statistics offer insights into overall performance metrics, such as the throughput of a junction. Stream-level statistics are also generated, offering a detailed view of performance at each stream. At every timestep, data is collected on whether an entity, such as a vehicle or pedestrian, is moving or stopped. This information is aggregated and presented at the end of the simulation for further analysis. For visual clarity, circles are marked on the layout to indicate locations where near-miss situations and incidents occurred, enhancing interpretability.

Shapes and Signs

Leveraging the capabilities of the Unity3D game engine, upon which MSV is entirely built, users can create a variety of 3D shapes to serve as visual aids. These can include 3D polygon shapes for pavement bases, traffic medians or dividers, traffic islands, and blocks to represent columns or slabs, among other elements. Users can also import images to serve as signs and markings, with options to position, scale, and rotate them as needed. Road names can be created in tools like Microsoft PowerPoint, converted into transparent PNG images using free software like GIMP, and then imported into the MSV environment. This removes language barrier and user can import signs and words in their own language. The visual appeal of the simulation plays a crucial role in presentations to non-technical stakeholders, ensuring that layouts are easy to understand. Basic signs, such as turn-arrows, are included with the installation files, but users can also create and import additional custom images to enhance the simulation’s visual clarity and communicative power.

Contact Us

To access User Manual for the MSV software, please click here.

To learn more about the author of the software, please click here.

If you have any questions, suggestions, or need assistance, feel free to reach out us. We’re here to help!

Email to (Dr Chandra)

drchandra@msvsoft.org