Smarter Transit System via Connected Vehicles and Low Cost

Internet of Things

June 21, 2018 B. Brian Park

Link Lab University of Virginia

Presented at the 5th Summer Conference on Livable Communities

Connected Vehicle based Transit Signal Priority

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What is TSP

! Transit Signal Priority (TSP) "  A control strategy that offers preferences to transit vehicles

at signalized intersections

! Conventional TSP Challenges "  Adverse effect on side streets "  Minor benefit "  Few buses can take advantage "  Uncertainty of benefit "  Not accommodating conflicting TSP requests

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Why TSPCV

! Incorporate V2X technology "  Transit Signal Priority with Connected Vehicle (TSPCV) "  Two-way communications "  better real time traffic information "  More accurate arrival time prediction "  Advanced TSP logic would be possible

! Recognized as “Day 1 application” "  AASHTO, USDOT …

4

TSPCV Logic

! Strategy "  Green time reallocation

•  Most buses are covered

! Bus cooperates with the traffic signal to perform TSP

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Green Reallocation

Queue cleared/ Bus arrival time

Bus arrival time range

Corresponding Green start time

Respect the original Phase

transition points Move part of the green forward

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Objective Function

! Minimize ( ∑𝑐𝑦𝑐𝑙𝑒=1↑𝑐𝑦𝑐𝑙𝑒=𝒏▒𝐷↓𝑖 ∗𝑂𝑐𝑐↓𝑖  +∑𝑐𝑦𝑐𝑙𝑒=1↑𝑐𝑦𝑐𝑙𝑒=𝒏▒𝐷↓𝑏𝑢𝑠 ∗𝑂𝑐𝑐↓𝑏𝑢𝑠  ) "  subject to: "  ∑𝑗↑▒(𝐺↓𝑗𝑏𝑒𝑓𝑜𝑟𝑒 + 𝐺↓𝑗𝑎𝑓𝑡𝑒𝑟 )+ 𝐺↓𝑇𝑆𝑃 + 𝐺↓𝑟𝑒𝑚𝑎𝑖𝑛 

=𝑐𝑦𝑐𝑙𝑒𝑙𝑒𝑛𝑔𝑡ℎ=𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡  "  𝑇↓𝑇𝑆𝑃𝑒𝑛𝑑 − 𝑇↓𝑇𝑆𝑃𝑠 = 𝐺↓𝑇𝑆𝑃  "  𝑇↓𝐵𝐴𝑙𝑜𝑤 ≤ 𝑇↓𝑇𝑆𝑃𝑒𝑛𝑑 ≤ 𝑇↓𝐵𝐴𝑢𝑝  "  𝑇↓𝑇𝑆𝑃𝑠 =∑𝑗↑▒𝐺↓𝑗𝑏𝑒𝑓𝑜𝑟𝑒   "  𝐺↓𝑗𝑏𝑒𝑓𝑜𝑟𝑒 + 𝐺↓𝑗𝑎𝑓𝑡𝑒𝑟 =𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡 "  𝐺↓𝑗𝑏𝑒𝑓𝑜𝑟𝑒 ≥ 𝐺↓𝑚𝑖𝑛  𝑜𝑟 𝐺↓𝑗𝑏𝑒𝑓𝑜𝑟𝑒 =0

"  𝐺↓𝑗𝑎𝑓𝑡𝑒𝑟 ≥ 𝐺↓𝑚𝑖𝑛  𝑜𝑟 𝐺↓𝑗𝑎𝑓𝑡𝑒𝑟 =0

"  𝐺↓𝑇𝑆𝑃 ≥ 𝐺↓𝑚𝑖𝑛  𝑜𝑟 𝐺↓𝑇𝑆𝑃 =0

"  𝐺↓𝑟𝑒𝑚𝑎𝑖𝑛 ≥ 𝐺↓𝑚𝑖𝑛  𝑜𝑟 𝐺↓𝑟𝑒𝑚𝑎𝑖𝑛 =0 "  Choice variables: G1before, G2before, G3before, and TTSPend.

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Evaluations

! Compare three scenarios "  No TSP "  Conventional TSP "  TSPCV

! MOEs "  Bus delay "  Person delay of all motorists

! Test network "  Emmet St. and Barracks Rd., Charlottesville, VA "  Field collected data (volume, signal timing)

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Evaluations

! Analytical test "  VBA in excel "  Theoretical benefit without randomness and uncertainties "  Evaluated all TSP possibilities, less biased

! Simulation test "  Randomness and uncertainties "  VISSIM "  Developed COM Interface

•  Access CV technology information •  Make changes to signal phasing in real time •  Assign desired speed to the bus

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Single Bus TSP Evaluation

0

50

100

150

200

250 1 6 11

16

21

26

31

36

41

46

51

56

61

66

71

76

81

86

91

96

101

106

111

116

121

126

131

136

141

146

151

156

Bu

s Tr

avel

Tim

e (S

ec)

TSP Activation Time (Sec)

Bus Travel Time

w/o TSP

with TSP

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Single Bus TSP Evaluation

Analytical Delay Comparison for One-Bus Scenario

v/c ratio NTSP CTSP TSPCV N/TSPCV C/TSPCV

Bus Delay (Sec)

0.5 57.7 50.3 5.3 -90.8% -89.5%

0.7 57.7 50.3 5.3 -90.8% -89.5%

0.9 57.7 50.4 5.9 -89.7% -88.3%

1.0 57.7 51.1 27.1 -53.0% -46.8%

Delay per person (Sec)

0.5 46.8 46.8 44.1 -5.6% -5.6%

0.7 46.8 46.8 44.1 -5.6% -5.6%

0.9 49.5 49.5 46.7 -5.6% -5.6%

1.0 51.1 51.1 48.3 -5.6% -5.5%

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Single Bus TSP Evaluation

MOE v/c ratio NTSP CTSP TSPCV N/TSPCV C/TSPCV

Bus Delay (Sec)

0.5 39.1 27.5 5.6 -85.7% -79.7%

0.7 40.6 29.2 4.8 -88.3% -83.7%

0.9 45.4 36.3 18.1 -60.1% -50.0%

1.0 48.7 34.0 30.9 -36.5% -9.2%

Delay per person (Sec)

0.5 36.1 33.0 30.9 -14.3% -6.2%

0.7 37.6 34.7 33.2 -11.6% -4.3%

0.9 42.8 39.2 40.3 -5.9% 2.6%

1.0 52.0 44.5 45.7 -12.0% 2.8%

STDDEV (sec) All 31 32 26 -16.1% -18.8%

Simulation Delay Comparison for One-Bus Scenario

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Measuring Transit Performances

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Motivations & Objective

!  In assessing or redesigning transit system, performance measures such as passenger waiting time at bus stop, and passenger origin-destination information are key

!  Small to medium size cities redesign transit system

(e.g., location of bus stops and even bus routes) without proper data

!  To develop and evaluate low cost technology based solution (Bluetooth or WiFi + Raspberry Pi)

Bluetooth, WiFi, and MAC Address

Bluetooth Readers for Link Travel Time Estimation

Field Data Collection (Device: Bluetooth/WiFi + Raspberry Pi)

Bluetooth & WiFi Readers: Hardware

!  Raspberry Pi 2 Model B (current version 3) !  Bluetooth Adapter !  WiFi Adapter !  5V/2A Portable Battery

Bluetooth & WiFi Readers: Software

! Raspbian Jessie Lite Operating System ! TShark ! Python Code

Comparison of Unique ID Samples

! Bluetooth/WiFi should be “on” to be detected

! Bluetooth IDs are about 1% of WiFi ! Why? iOS & Bluetooth “off”

Bluetooth WiFi

Chemistry Building 15 1,789

Garrett Hall 14 1,696

Based on MAC Address collected during an hour on Monday, March 21, 2016

Technology Verification with Known Device

Bus # Time on Bus

–Field Verification

Time off Bus – Field Verification

Estimated Trip

Duration (sec)

Time on Bus – Reader

Verification

Time off Bus – Reader

Verification

Duration of Trip (sec)

1 17:34 17:36 - - - -

2 17:51 17:54 120-240 17:51:39 17:54:29 170

3 18:03 18:06 120-240 18:03:41 18:06:54 193

4 18:25 18:26 - - - -

Average 180 Average 181.5

Passenger Bus Stop Waiting Time

Bus #

Chemistry Building (#65) Garrett Hall (#63)

MAC Detected

Bus Arrival Time

MAC Disappeared

Bus Stop Waiting Time MAC

Detected Bus Departure

Time

1 17:32:39 17:34 17:33:58 0:01:19 17:36:53 17:36

2

17:49:09

17:51

17:51:13 0:02:04 17:54:10

17:54

17:28:18 17:51:11 0:22:53* 17:53:14

17:49:09 17:51:21 0:02:12 17:54:10

17:51:11 17:51:35 0:00:24 17:53:53

17:50:24 17:51:27 0:01:03 17:53:16

3

18:02:56

18:03

18:03:14 0:00:18 18:06:15

18:06 17:59:43 18:03:14 0:03:31 18:06:12

17:59:07 18:03:49 0:04:42 18:06:06

18:02:56 18:03:30 0:00:34 18:06:15

4 18:25:17 18:25 18:25:31 0:00:14 18:26:47 18:26

Sample Rate & Passenger OD Information

Bus #

Chemistry Building Garrett Hall Origin Destination

MAC Detected Bus

Arrival Time

# pax onboard

# Devices Detected

MAC Detected

Bus Departure

Time

Travel Time (sec)

Sample Rate

1 17:32:39 17:34 2 1 17:36:53 17:36 254 50%

2

17:49:09

17:51 9

4

17:54:10

17:54

301

44%

17:28:18 17:53:14 1496*

17:49:09 17:54:10 301

17:51:11 17:53:53 162

17:50:24 17:53:16 172

3

18:02:56

18:03 16 4

18:06:15

17:06

199

25% 17:59:43 18:06:12 389

17:59:07 18:06:06 419

18:02:56 18:06:15 199

4 18:25:17 18:25 4 1 18:26:47 17:26 90 25%

Low Cost Solution

! Dedicated Short Range Communication (DSRC) "  Roadside Unit: $2-3K "  Onboard Unit: $2K "  Latency: 100 ms

! LoRa Wide Area Network (LoRaWan) "  LoRa Gateway: $1-2K "  LoRa end node: ~$50 "  Low power and long range "  Each Gateway supports up to 20K IoT devices "  Latency: 1-2 seconds

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LoRa Technology

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Collaborators: Samy El-Tawab (JMU)

Jia Hu (Tongji U) Saerona Choi (KTSA)

John Whittier & Seunghan (Francis) Ryu (UVA)