This document discusses new directions for evaluating transportation level of service (LOS) standards to avoid undesirable outcomes. It presents three key ideas: 1. Existing LOS standards that prioritize high vehicle speeds and traffic flow can have negative consequences like increased emissions, loss of open space, and prioritizing driving over other modes. 2. Case studies show alternatives like dedicated bicycle phases or grade-separated crossings that benefit other modes can improve safety and mobility without worsening vehicle LOS. 3. Reconsidering LOS thresholds to balance multiple goals like open space, air quality, and development patterns can support more sustainable outcomes than speed-based standards.

1. New Directions in Transportation LOS -
How to Avoid a Failing Grade
Presented by
Ronald T. Milam, AICP, PTP
CNU 17 – June 12, 2009

2. Consequences of Current Practice
Existing Conditions:
LOS E

3. Consequences of Current Practice
Widening for LOS C
• Longer crosswalks
• Loss of riparian habitat
• Increased impervious surface
• Higher vehicle speeds
• Greater consumption of
physical space

4. LOS, Speed, and Emissions
Relationship of Freeway LOS, Speed, and CO2 Emissions Factors
Relationship of Freeway LOS, Speed, and CO2 Emissions Factors

5. Consequences

6. Physical Space

7. Physical Space – Design Standards
Early 20th Century
Area dedicated to
driving and parking
= 21.5%

8. Physical Space – Design Standards
Early 21st Century
Area dedicated to
driving and parking
= 37.5%

9. Case Study: Davis, CA
Study Location

10. Case Study: Davis, CA
• Alternative 1: Provide all pedestrian/bicycle signal phase
• Alternative 2: Provide exclusive phase only for southbound (SB)
and westbound (WB) cyclists who travel on a Class I bicycle bath.
Cyclists traveling on other approaches would travel with vehicles
using the regular vehicle signal phase.
• Alternative 3: Traditional design (no exclusive bicycle and
pedestrian phases)
• Alternative 4: Provide five-second “head-start” phase for SB and
WB cyclists traveling on Class I bicycle path.
• Alternative 5: Provide grade-separated bicycle crossing connecting
SB and WB Class I bicycle paths

11. Case Study: Davis, CA
Seconds of person delay

12. LOS Threshold Trade-offs
Open Space
Open Space
Air Quality/
Air Quality/
Climate Change
Climate Change
Other Modes
Other Modes
Costs
Costs
Transit-Oriented
Transit-Oriented Infill Development
Development Infill Development
Development

13. Proximity vs. Speed

14. Proximity-Based Development
• Early America

15. Speed-Based Development
• Post World War II

16. LOS, Speed, and Emissions
Relationship of Freeway LOS, Speed, and CO2 Emissions Factors

17. LOS, Speed, and Emissions
Relationship of Arterial LOS, Speed, and CO2 Emissions Factors