Is Transportation Sustainable?

Objectives

By the end of this unit, students will be able to:

1. Examine and prioritize transportation project impacts on sustainability

2. Recognize transportation project solutions’ impacts on sustainability

3. Identify mitigation strategies for transportation solutions to reduce negative impacts on sustainability

4. Identify transportation sustainability metrics

5. Explain the aspects of transportation projects that may affect sustainability

Sustainability in TransportationAir Quality

Alternative Modes

Congestion

Construction Materials

Transportation Sustainability Measures Vary from project to project

How to measure congestion?

What about air quality related to transportation?

Can alternative travel modes be measured?

Other considerations: Safety Fuel consumption O&M or life cycle sustainability

Land Use

Water Quality and Volume

Actual Cost of TransportationFuel and vehicle

Delay/congestion

Traffic Signal RetimingWhat are goals?

Can we measure the goals?

Air quality

Safety

Social

Infrastructure maintenance

Case Study: What to do at an intersection?Traffic Signal

Two-way Stop

Four-way Stop

Traffic Circle

Roundabout

What Metrics to Consider?Technical

Sustainability Economic Environmental Social

Constructability

Political Will

Others?

Traffic Signal CharacteristicsOperating and Maintenance cost

Controller Communications Signals Retiming

High speed crashes may occur

Can handle large volumes

Other information needed?

StopsLow O&M costs, but signs must be periodically

replaced

What are the functional classifications of the intersecting roadways? May dictate, 2 vs. 4 – way stop

Speed of crashes varies based on the functional classifications; however, 4-way stop crashes are typically low speed

Other information to collect?

Traffic CircleCharacteristicsLow capacity

Minimal, if any O&M

May accent neighborhood

Low speed, often local facilities

Other information?

Reference: http://www.ite.org/traffic/circle.asp

RoundaboutCharacteristicsMinimal O&M cost

Relatively high capacity

Bike/Ped. safety

Lower speed crashes than signalized intersections

Other necessary information?

Reference: http://www.kittelson.com/kai_toolbox/roundabouts/index.htm

Put it All TogetherChoose an alternative analysis methodology

Combine metrics

Evaluate alternatives

Recommend alternative

Class ActivityWhat are the proposed project’s impacts on

sustainability? Rank order these in terms of importance and

magnitude

What are the appropriate metrics for assessing the project’s impact on sustainability?

Identify possible strategies for reducing the project’s negative impact on sustainability

Group Projects INSERT LOCAL TRANSPORTATION PROJECTS

References www.ite.org/traffic/circle.asp

www.kittelson.com/kai_toolbox/roundabouts/index.htm