1. Methodology and Results
Preliminary Evidence of Complete Streets Effects on Bus Operations using Automated Data Sources
Abubakr Ziedan PhD Student 1 , Candace Brakewood Assistant Professor 1 , Philip Pugliese Transportation Planner 2
1 University of Tennessee | 2 Chattanooga Area Regional Transportation Authority
Contact: Abubakr Ziedan: | Candace Brakewood: | Philip Pugliese:
Background
Methodology and Results
What are Complete Streets?
Streets for everyone
Designed to enable safe access for all users, including pedestrians, bicyclists, motorists and transit riders of all ages and abilities
Motivation
More than 1400 complete streets policies have been adopted in the period from 2004 to 2018 across the United States
The proliferation of complete streets policies nationwide has contributed to roadway redesigns
Complete streets redesigns often result in a reduction of travel lanes that may affect both motorists and transit operators
Limited number of studies investigated the effect complete streets on transit operation
Objective
The objective of this study is to explore the potential effects of complete streets implementation on bus operations using Automatic Vehicle Location (AVL) data
Area of Analysis
Chattanooga, Tennessee is a mid-sized city with an estimated population of 179,139
The City of Chattanooga adopted a complete streets policy in 2014.
Roads redesigned along Brainerd Road and Martin Luther King, Jr. Boulevard (MLK Blvd.) according to complete streets policy.
These road redesigns were implemented December 2017 for Brainerd road and in April 2018 MLK Blvd
Road Redesign
The redesign of these road included :
Introduced bike infrastructure along Brainerd Road (Figure 2)
Road diet on MLK Blvd. (Figure 2)
Analysis Time Periods
Performance Measures
The following performance measures were used to evaluate complete streets impacts on bus operation:
Headway reliability
Percent On-Time Performance (OTP) by timepoint
Mean segment speed
Results
Bus Reliability
Headway Reliability
The percentages of acceptable spaced trips, bunched trips and gapped trips were very similar for the different analysis periods for both directions (Figure 3)
Timepoints Percent On-Time Performance (OTP)
For the outbound direction, the observed differences were small variations and do not provide any evidence of bus OTP changes associated with these road changes
For the inbound direction, there were some improvements in some timepoints but these improvements were not expected since no road changes could cause them.
Bus Speed
Mean speed per segment was compared for the three analysis periods
Statistically significant changes were noticed only for the PM peak period Statistically significant decrease in bus mean speed for the outbound direction were noticed when the roadway design speed and the travel lanes were reduced as expected (Table 1)
For the inbound direction, there was no clear trend or statistically significant changes for mean speed in the segments with bike infrastructure (Table 2)
The statistically significant changes in bus mean speed were noticed in the last segment. This changes are not expected since there were no changes in this segment (Table 2)
Conclusions and Future Research
Bus speed was affected significantly when the road design speed or road capacity was reduced, but this impact is limited to the PM peak period
Implementation on complete streets design elements did not significantly affect bus reliability
Results suggest that in areas without significant congestion, complete streets implementation may not have a significant impact on transit operations
Future research should investigate the long term impacts of complete streets on transit in Chattanooga
Future research should also evaluate different complete streets projects in other regions on roads with different levels of vehicular traffic
References
National Complete Streets Coalition | Smart Growth America. Accessed 07/18/2018.
U.S. Census Bureau Quick Facts: Chattanooga city, Tennessee. Accessed 07/10/2018.
MLK Blvd. Before Road Diet
MLK Blvd. After Road Diet
Traditional Design
Complete Streets Design
• Car Centric
• Wide Travel Lanes
• Higher Speed limits
• Limited Accessibility for other Modes
• Designed for All Road Users
• Wider and Better Sidewalks
• Pedestrian Refuge Islands
• Bike Lanes
• Transit Lanes
• Center Turn Lanes
Table 1: Bus speed for the outbound direction for PM peak period
Segment
Mean Speed (MPH)
Before Period vs
After Period 1
After Period 2
After Period 1 vs
Before
After 1
Difference
After 2
Market & 4th to Bailey & Willow
(MLK Blvd. road diet)
11.45
11.49
0.04
10.72
- 0.73**
- 0.77**
Bailey & Willow to Brainerd & Germantown
(Brainerd bike infrastructure)
17.47
15.51
- 1.96**
16.32
- 1.15
0.81
Brainerd & Germantown to Brainerd & Walmart (Brainerd bike infrastructure)
14.30
14.45
0.15
14.74
0.44
0.29
Brainerd & Walmart to Hamilton Mall
(Last segment)
13.35
14.27
0.92**
14.50
1.15***
0.23
Significance: * p<0.10; ** p<0.05; *** p<0.01
Brainerd Road Before Bike Infrastructure
Brainerd Road After Bike Infrastructure
Figure 2: Bus Route #4 Corridor and Road Changes
Period 1 : October 2017
Base case scenario
Period 2 : January 2018
After Brainerd road bike infrastructure
Period 3 : June 2018
After both road changes
Figure 1: Complete Streets Design vs Traditional Design
Table 2: Bus speed for the inbound direction for PM peak period
Segment
Mean Speed (MPH)
Before Period vs
After Period 1
After Period 2
After Period 1 vs
Before
After 1
Difference
After 2
Hamilton Mall to Brainerd-Walmart
14.53
14.76
0.23
14.52
- 0.01
- 0.24
Brainerd & Walmart to Brainerd & Germantown
(Brainerd bike infrastructure)
15.85
15.48
- 0.37
16.16
0.31
0.68
Brainerd & Germantown to McCallie & Willow Street
20.88
20.12
- 0.76
21.24
0.36
1.12
McCallie & Willow Street to Market & 4th
(Last segment)
9.82
10.51
0.69**
9.51
- 0.31
- 1.00**
Significance: * p<0.10; ** p<0.05; *** p<0.01
Outbound direction
Inbound direction
Figure 3: Bus Route #4 Headway Reliability
ACKNOWLEDGMENT
The authors would like to acknowledge the City of Chattanooga and Chattanooga Area Regional Transportation Authority (CARTA) for providing the data for this study