3M - AI-driven Intersection Safety Diagnostics

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Top 3 Challenges Every City Cares About

01

02

03

Improving Safety

Congestion and Air Quality

Transportation Equity

Traffic congestion and limited urban space create major strain on existing infrastructure.

Access to safe and sustainable mobility for all age groups, gender and income groups

Solutions to urban safety and accessibility problems will evolve in tandem with cities Improving roadway safety is a top priority, driven by the trend for sustainable urban mobility

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Challenges to Cities

Cities are challenged to meet these transportation revolutions Improving roadway safety for vulnerable road users in urban areas is a top priority.

In urban areas 70% of fatalities are vulnerable road users. Pedestrians and cyclists account for 29% of all road deaths in the EU. Source: Facts and figures (europa.eu)

Good progress for car passenger safety, no improvements in cyclist safety in past 10 years. Increasing urbanization leads to more conflict between vulnerable road users and motorized transport. Source: ETSC European Transport Safety Council

It is expected that almost 84% of all Europeans will live in cities by the year 2050.

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Integrated Space management New and integrated approaches of using and managing urban space, as expressed in policies such as placemaking, access regulation or kerbside management Source: Prognose zum Anteil von Stadt- und Landbewohnern in den Weltregionen bis 2050 | Statista


Power Metrics

5527 Pedestrian deaths in EU in 20171

70% in urban areas1

33% of traffic fatalities in urban areas happen at dawn or darkness2 Source: 1 Road Safety Facts & Figures | Mobility and transport (europa.eu) 2 Verkehrsunfälle in Deutschland - Statistisches Bundesamt (destatis.de) © 193M April 2022 . All Rights Reserved.


38% of traffic related fatalities happen inside urban areas

Source: CARE (EU road accidents database)

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Improving Intersection & Traffic Signal Safety in Response to Video Based Near Miss Analysis: City of Austin Smart Mobility Pilot Pilot Sponsor: • Jason JonMichael, Assistant Director - Austin Transportation Department / Head of Smart Mobility Office • Joseph McKenzie, Project Manager – Smart Mobility Office

4/19/2022


City of Austin - Smart Mobility Office How We Got Here

ASMP Challenge #1 - Safety Austin Strategic Mobility Plan (ASMP) • •

Adopted in 2019 The Austin Strategic Mobility Plan is a comprehensive multimodal transportation plan for the future of our transportation network - and it is needed for Austin to achieve the mobility outcomes that will help to improve and sustain the quality of life for all community members.

• •

Challenge #1 - How might we lower the risk of travel-related injury and protect and promote public health? Safety Culture Policy 4 states: “Testing and piloting technologies will give us the opportunity to examine and analyze how new technology is integrated into the transportation network and the chance to identify necessary safety precautions”


Public/Private Partnerships Pilot Program Smart mobility involves utilizing new technologies to move people and goods through our city in faster, safer, cleaner, more affordable and more equitable ways. •

Visit Austintexas.gov/smart -mobility

Complete the online “Expression of Interest” form to start the process


3M / MicroTraffic Pilot Project Locations Selected: • Part of Vision Zero’s High Injury Network Project’s Municipal Purpose: • Vision Zero - Reduce risks to health and increase public safety • Testing the viability of a new technologies • Improve partners hip development and systems development testing Testing of Emerging Technology • AI Detection and Tracking of Near Misses • Uses Existing Transportation Management Cameras Test Effectiveness of Various Urban Safety Solutions Three Phase Pilot • Current Conditions Analysis & Reporting • Safety Improvements Implementation • Post Improvements Analysis & Reporting


Why diagnose with near-misses? Out of Date Underreported

Crash Data Problems

Errors

Small Clusters

Reactive

Surrogate: A non-crash measure of risk that proactively reveals risk factors with reliable sample sizes. For more information: TRB ACS20(3) Subcommittee


What is a near-miss (traffic conflict)? • A traffic conflict exists either when two road users are travelling towards the same point such that a collision would have occurred if one of the road users did not perform an evasive action. • A traffic conflict also exists when there is an insufficient safety margin between two road users who cross paths. • Risk = likelihood X severity • Likelihood is a function of proximity (in time or space) • Severity is a function of speed, angles, and kinetic energy


MicroTraffic Diagnostic Technology (1) Measuring trajectories from video using AI


MicroTraffic Diagnostic Technology (2) Extracting safety indicators from trajectories


Near-miss classification based on chance of injury Probability MAIS3+ Injury Severity

VEH-VRU

VEH-VEH

Low

<5%

<10%

Med

5%+

10%+

High

40%+

40%+

Critical

85%+

85%+


Key figures from video diagnostics 94%

Validated accuracy of video diagnostic risk indicators for predicting injury collisions1

80%

Typical risk reduction achieved when responding to video diagnostics

36X

Faster measurement of safety improvement compared to crash data before-after studies

Anarkooli, Persaud, Milligan, et. Al (2021). Transportation Research Record.

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Location #01 Lamar Blvd & Morrow St N Lamar Blvd is a major N S arterial running parallel to I 35 and providing access to downtown Austin. Just north of the intersection is a grade separation for US 183 and related frontage roads. Morrow St is a minor E W collector serving residential land use to the west and residential, commercial, and educational to the east. It is a designated medium comfort bike route.


EBR vs PED W Side T2 = 0.4s ; V = 2 mph Note this conflict occurs during EB RTOR –driver attention is to the left for gap search task.



C u r r e nt l y i n s t a l l i ng i m p r o v e m e nt s

P o s t I m p r ov e m e n t An a l ys i s t o b e c o n d uc t e d i n e a r l y 2 0 2 2


Artist renderings



Site Location • Pleasant Valley Rd is a major N-S arterial running parallel to I-35, providing access from east Austin to destinations south of the river. Designated bike lanes are present on both sides of the road in the vicinity of the intersection.

• Elmont Dr is a minor E-W collector serving residential land use to the east and residential, commercial to the west. It is a designated medium comfort bike route. • The intersection is just north of the South Pleasant Valley Road Corridor Mobility Plan study area.


Looking South – S. Pleasant Valley

• • • • • •

4 lanes + two-way-left-turn-lane Narrow raised median at intersection Protected-permissive NBL 35 mph posted speed limit 3 signal displays, no backplates Designated bike lanes on each sidewalk


Looking North – S. Pleasant Valley

• • • • • •

4 lanes + two-way-left-turn-lane Narrow raised median at intersection Protected-permissive SBL 35 mph posted speed limit 3 signal displays, no backplates Designated bike lanes on each sidewalk


Looking West – Elmont Drive

• • • • • • •

One through lane in each direction Designated EBL left turn lane (permissive) Raised median with boulevard at intersection 30 mph posted speed limit Access to convenience store <100 ft from intersection Bus stop on south side of Elmont 3 signal displays, no backplates


Looking East – Elmont Drive

• • • • • • •

One through lane in each direction Designated WBL left turn lane (permissive) Raised median with boulevard at intersection Eastbound U-turn yield 200 ft from intersection Access to residential townhouses <100 ft from intersection Bus stop on south side of Elmont 3 signal displays, no backplates


Historic Collision Data 2012-15 (Pre Improvements)

PDO Injury Total

% Ttl

Pre Post Avg/yr Avg/yr

Left Turn Across Rear End Left Turn Conflict Right Angle Bicycle Pedestrian Sideswipe - Same Dir Struck Object

7 4 0 1 0 0

14 15 3 2 2 2

21 19 3 3 2 2

40% 37% 6% 6% 4% 4%

5.3 4.8 0.8 0.8 0.5 0.5

1 1

0 0

1 1

2% 2%

0.3 0.3

Total

14

38

52

13

2 4 1 2 1

10

Speed limit reduction, protected permissive phasing, and crossing improvements implemented prior to this study.


• Police records state speed as contributing factor in several collision records

• Red light running resulted in 3 collisions (2 injury) in 2019 (2 SB, 1 EB), but only stated as a factor in 2 collisions in previous 2012-2015 data • 50% of collisions occurred after 17:00 in 2019 data and 37% after 17:00 in 2012-2015 data

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Frequency

Historic Collision Data - Contributing Factors

Time of Day

Temporal Variation by Time of Day (2012-2015)

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Vehicle - Vehicle Key Issues • Speeds along Pleasant Valley (Northbound and Southbound) • “New” 35 mph speed (posted after March 2019 according to Google) • Rear End Collisions • High potential impact speeds with turning vehicles • Left turn vs Oncoming Vehicle Configurations • This configuration represented 40% of all collisions in 2012-2015 • Reduced to 20% of all collisions in 2019 data • Risk for this movement is still evident in the conflict data • Red light running • 2 events reported this as a behavioral factor in 20122015 • 3 events reported this as a behavioral factor in 2019 alone (during daylight hours) • Despite limited view of signals, one violation was observed in conflict data

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Red light violation WBT

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Southbound through speeds

Posted Speed Limit

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Northbound through speeds

Posted Speed Limit

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23% of all collisions from 20122015 but after construction only 10% of all collisions in 2019

Vehiclevehicle nearmisses from MicroTraffic video analytics

12% of all collisions from 20122015 but after construction, 0% reported in 2019

WBL vs NBT

EBL vs SBT

SBL vs WBT

NBL vs EBT

NBT vs WBT

EBT vs SBT

SBT vs WBT

NBT vs EBT

WBL vs EBT

EBL vs WBT

SBL vs NBT

NBL vs EBT

These conflicts relate to signal violations/ proceeding at the end of phase. EBT vs SBT and EBL vs SBT each had recorded red light running collisions in 2019


SBL vs NBT conflicts (protected permissive phasing)


NBL vs SBT conflicts (protected permissive phasing)


Vehicle - VRU Key Issues • VRU collisions represented 10% and 17% of all injury collisions in 2012-2015 and 2019 respectively: • 2 pedestrian and 2 cyclist collisions in 2012-2015 • 2 cyclist collisions in 2016 (dark lighting condition) • 1 pedestrian collision in 2019 (dark lighting condition) • Vehicle Left-Turn Speeds • High frequencies of left and right hook conflicts • Conflict rates for various movements often exceed the benchmark for similar sites

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Cyclist conflict at low light conditions

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Left Turning Speeds

Risk of Severe Injury (MAIS 4+) to a Pedestrian (Tefft, 2012) • 10% at 14 mph • 15% at 20 mph

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Average Speed (mph)

85th Percentile Speed (mph)

SouthboundLeft

15

17

NorthboundLeft

12

14

WestboundLeft

12

14

EastboundLeft

14

16

37


Vehicle-Pedestrian Conflicts

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South-Left Hook Low Risk Events: North-Right Hook Medium Risk Events: 4.3x higher than benchmark 3.3x higher than benchmark

West-T/L/R nearside

West-through farside

West-Right Hook

West-Left Hook

South-T/L/R nearside

South-through farside

South-Right Hook

South-Left Hook

East-through far side

East-Right Hook

East-Left Hook

North-T/L/R nearside

North-Right Hook

North-Left Hook

Vehiclepedestrian near-misses from MicroTraffic video analytics

North-through farside

East-Left Hook Low & Medium Risk Events: 3.0x higher than benchmark

East-T/L/R near-side

West-Right Hook Low & Medium Risk Events: 3.2x higher than benchmark


Pedestrian – West-Right Hook

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West-T/L/R nearside

West-thru far-side

West-Right Hook

West-Left Hook

South-T/L/R nearside

South-thru far-side

South-Right Hook

South-Left Hook

East-T/L/R near-side

East-thru far side

East-Right Hook

East-Left Hook

North-T/L/R nearside

North-thru far-side

North-Right Hook

North-Left Hook

Vehicle-cyclist near-misses from MicroTraffic video analytics For 1000 cyclists using the North Crossing, ~53 users will experience a low risk conflict event and ~37 will experience a medium risk conflict event


Cyclist – West-Right Hook

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E-scooter conflicts • MicroTraffic detects pedestrians with 93.8% accuracy. • 65 e-scooters detected • 5 low and 1 medium risk conflict (50% of these vs WBR) • Emerging field within surrogate safety • Important due to absent crash history


Key Issues and Recommendations Key Risk Issue

Proposed Mitigation

High Speeds

• Consider speed management techniques, such as centerline hardening on the NB/SB approaches • Increase enforcement • Assess current protected left phase length in relation to turning volumes throughout the day • Improve nighttime intersection visibility to address disproportionate frequency of conflicts after 19:00 • Consider protected-only left turn phasing

Southbound/North bound LTAP (relative risk is 1.6 and 2.4x higher than benchmark conflict rates) Red Light Running • Improve signal system visibility with reflective backplates Review amber and all red times • Consider changing span wire signals to master arm at dual elevations in the future to increase conspicuity

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Key Issues and Recommendations Key Risk Issue

Proposed Mitigation

VRU left hook conflicts (SBL, NBL and EBL each result in several medium risk conflicts)

VRU right hook conflicts (WBR and NBR movements both result in several medium risk conflicts)

Implement actuated Leading Pedestrian (Bicycle) Interval to increase VRU visibility on crossing

VRU conflicts (in general)

Increase separation between modes. Consider a Dutch style protected intersection design if cyclist/ pedestrian volumes are expected to increase as VRU network connectivity improves Provide improved crossing conspicuity for cyclist crossing and crosswalk Improve nighttime intersection visibility to address pedestrian conflict/collisions observed after 19:00

• •

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Consider restricting permissive left turns during peak periods where drivers are focused on seeking gaps in oncoming traffic Provide centerline median hardening (polyposts and mountable rubber curb) to calm left turns and provide overall speed moderation on the NB/SB approaches

45


Austin Texas Pilot Summary • 3 intersections diagnosed • 1 mobility hub diagnosed • 1 intersection diagnosis in progress

5 more intersections contracted by Austin post-pilot TxDOT TP&P Line-Item Approval January 2022.

• 2 intersections partially improved with high retroreflective treatments • 1 intersection deferred for capital program synchronization • 1 intersection pending initial diagnosis • After studies pending at all intersections to measure risk reduction


Thank You Questions?


Thank You Visit us at Intertraffic Amsterdam 29 MAR – 1 APR 2022, Hall 1, booth 01.253


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