Appendix H. Visualization Techniques

 

H.1. Models and Simulations

In many cases, traffic operational issues are a concern either to technical stakeholders or the general public. Traffic operational concepts can be difficult even for technical professionals to grasp. The effects, for example, of increased traffic on queuing, delay, and operations are not linear, and are often not well understood. Simulating vehicles or vehicle streams through complex locations such as closely spaced intersections, or through roundabouts, is a useful tool to demonstrate operations.

 

Best practices include FHWA's CORSIM model (which provides detailed quantitative output and animation of traffic operations through an integrated network comprised of arterial streets and freeways). Other software tools include VISSIM, SIMTraffic, Parametric, and Synchro.

VISSIM

VISSIM is a microscopic, behavior-based multi-purpose traffic simulation program. Typical uses include:

 

Analysis of existing conditions and low cost retiming efforts.

 

Comparison of design alternatives (roundabouts, intersections, and grade separated interchanges)

 

 

 

 

Traffic management systems analysis, such as alternative route control, traffic flow control, access control and special lanes

 

Feasibility analysis of large networks (e.g., motorways) with alternative route choice using dynamic assignment

 

Engineering tasks, such as capacity analysis of railroad block section

 

Simulation of traffic-calmed areas including all relevant road users

 

Simulation and visualization of pedestrian flows, such as at a transit interchange (bus and metro).

 

Image and information source: ptv Traffic Mobility Logistics

SIMTRAFFIC

SimTraffic performs micro simulation and animation of vehicle traffic. With SimTraffic, individual vehicles are modeled and displayed traversing a street network. SimTraffic models signalized and unsignalized intersections, and freeway sections with cars, trucks, pedestrians, and busses are be modeled. Unlike some of the competing models, animation is displayed while the simulation is performed. Input is very easy and productive, in most cases all that is needed is the same data used within Synchro. Image and Information Source: http://www.trafficware.com

 

Synchro

The greatest value can be obtained from simulations where calibration (i.e., replication of operations as they occur and are observable by stakeholders) is possible. Simulation then can be particularly effective in showing, for example, the queuing and resulting other problems that might occur if no action were taken and traffic increased.

 

Additional information on these and other traffic analysis tools can be found in FHWA’s Online Traffic Analysis Toolbox (http://ops.fhwa.dot.gov/trafficanalysistools/toolbox.htm)

H.2. Illustrations

Sketches/illustrations can be used to communicate a variety of concepts throughout planning and design. 

Illustrated Plan Views

An illustrated plan view is a view of the project taken from directly above that is graphically enhanced.  Illustrated plan views are one way intended landscaping can be communicated to the public, as in the below image of U.S. 1 in Cocoa, Florida:

 

 

Source:  Ivey Harris & Walls.  Cocoa, Florida US 1 Final Design Widening

 

Cross Sections 

There are numerous ways to illustrate project cross sections so that stakeholders have a better understanding of design dimensions:

 

Simply adding vehicles to a typical cross section provides a point of reference for a super-elevated section of Eagles’ Landing Parkway, shown below:

 

 

 

 

Source: GDOT Public Outreach Website - Eagles Landing Parkway Project

  

Adding landscaping and aesthetic treatments in addition to pedestrians and vehicles adds to the visual appeal of this cross section for Dr. Martin Luther King, Jr. Blvd. in Savannah, Georgia:

 

 

 

Source: Dr. Martin Luther King, Jr. Boulevard.  Savannah, GA

 

 The below 3-dimensional, bird’s eye view of the GA400 was used recently at the Public Information Open House:

 

 

 

 

 

 

 

Source: Public Information Open House Displays for GA400 NH 056-1(59) PI #722010

Isometrics

An isometric is a type of 3-dimensional drawing that does not use perspective. An isometric drawing shows two sides of the object and the top or bottom of the object. 

 

Isometric drawings can be used to illustrate how proposed improvements will fit into the community landscape from a broad perspective or in relation to landmarks, as shown in the images below. 

 

 

 

 

 

 

 

 

 

 

 

 

 

A rendering of a section of the I-16/I-75 Project in Macon, GA - Second St. from Walnut St. to Emery Hwy. Inset is the existing highway Source:  GDOT, http://www.i16i75.com

 

 

 

 

 

 

 

An isometric drawing of the proposed 14th Street Bridge

Source: http://www.midtownalliance.org/TI_14and15.htm

Renderings

Renderings are typically photo-realistic 3-dimensional drawings in perspective of proposed improvements to a facility. Consider using renderings to illustrate before and after scenarios for proposed alternatives.

 

 

 

 

 

 

 

Source:  Parsons.  Richmond, NY Traffic Improvement Study