1

Bicyclist Ride Quality: Preliminary Results

Hui Li, Ph.D.

UC Pavement Research Center (UCPRC)

University of California, Davis & Berkeley

Nov 12th, 2013

SLO County Bike Advisory Committee Meeting

2

Outline

Macrotexture Measurement

Bicycle Vibration Measurement

Survey on Bicyclist Ride Quality

Additional Survey

Remedial Treatment on SLO-1

Remarks

3

Macrotexture Measurement

Laser Texture Scanner (LTS)Spot block measurement with need for traffic closure

Inertial Profiler (IP)Continuous linear measurement without need for traffic closure

Mean Profile Depth (MPD)Unit: mm or in

4

MPD (example): Continuous measurement w/ IP

85 90 95 100

0123456

Postmile (km)

MP

Dm

m

53.1 56.2 59.4 62.5Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_51.3-62.5_NB_SHLDR

100 105 110 115

0123456

Postmile (km)

MP

Dm

m

62.5 65.6 68.8 71.9Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_62.5-74.3_NB_SHLDR

100 105 110 115

0123456

Postmile (km)

MP

Dm

m

62.5 65.6 68.8 71.9

Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_74.3-62.5_SB_SHLDR

85 90 95 100

0123456

Postmile (km)

MP

Dm

m

53.1 56.2 59.4 62.5Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_62.5-51.3_SB_SHLDR

85 90 95 100

0123456

Postmile (km)

MP

Dm

m

53.1 56.2 59.4 62.5Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_51.3-62.5NB_WP

100 105 110 115

0123456

Postmile (km)

MP

Dm

m

62.5 65.6 68.8 71.9Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_62.5-74.3_NB_WP

100 105 110 115

0123456

Postmile (km)

MP

Dm

m

62.5 65.6 68.8 71.9

Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_74.3-62.5_SB_WP

85 90 95 100

0123456

Postmile (km)

MP

Dm

m

53.1 56.2 59.4 62.5Postmile (mile)

00.040.080.120.160.20.24

MPD

(in)

SLO1_62.5-51.3_SB_WP

HMA

HMA

Bridge

Bridge

51 6 2 5 3 4 7 16 8 15 9 14 10 13 11 12 17 18 19 20 21 22 23

0

1

2

3

4

Survey Section #

MP

D (

mm

)1, 6 = 5/16 in PME Seal Coat2, 5 = Modified Binder Seal Coat - Modified gradation3, 4 = Modified Binder Seal Coat - Utilizing steel roller7, 16 = Cinder Seal8, 15 = Microsurfacing9, 14 = 1/4 in PME Seal Coat - 2nd application of a double chip seal10, 13 = Sand Seal11, 12 = Slurry Seal17, 18 = Old HMA Overlay on Mon-19819, 20 = New Chip Seal on Mon-198 (Control)21-23 = New Chip Seal on SLO-1 (Control)

Sand Seal

Chip SealOn Mon-198

Chip SealOn SLO-1

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Bicycle Vibration Measurement

Accelerometers (solid red circles) GPS unit (dot blue circle)

71 6 2 5 3 4 7 16 8 15 9 14 10 13 11 12 17 18 19 20 21 22 23

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Survey Section #

Bic

yc

le V

ibra

tio

n A

z (g

)1, 6 : 5/16 in PME Seal Coat2, 5 : Modified Binder Seal Coat - Modified gradation3, 4 : Modified Binder Seal Coat - Utilizing steel roller7, 16 : Cinder Seal8, 15 : Microsurfacing9, 14 : 1/4 in PME Seal Coat - 2nd application of a double chip seal10, 13 : Sand Seal11, 12 : Slurry Seal17, 18 : Old HMA Overlay on Mon-19819, 20 : New Chip Seal on Mon-198 (Control)21-23 : New Chip Seal on SLO-1 (Control)

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Bicyclist SurveyAcceptability (0 = Unacceptable; 1 =

Acceptable): average rate of acceptability or percentage of riders rating pavements as “Acceptable”.

Ride Quality: 1 to 5, with 1 = Poor and 5 = Excellent.

Other background information with potential correlations.

GroupSection

#

Rider

#

Mon-198 16 24

SLO-1 3 11

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MPD(mm)

0.4 0.6 0.8 1.0

0.90 0 . 0 1

0.0 0.2 0.4 0.6 0.8 1.0

-0.850.5

1.0

1.5

2.0

2.5

3.0

-0.88

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Vibration Az(g)

0 . 0 0 -0.94 -0.96

Speed(mph)

-0.23

11

12

13

14

15

16

17

-0.13

0.0

0.2

0.4

0.6

0.8

1.0

Acceptability(rate) 0.95

0.5 1.0 1.5 2.0 2.5 3.0 11 12 13 14 15 16 17 1.5 2.0 2.5 3.0 3.5 4.0

1.5

2.0

2.5

3.0

3.5

4.0

Ride Quality(level 1 - 5)

Scatterplot Matrix (Mon-198 + SLO-1)

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Remedial Treatment on SLO-1Preliminary measurement just after construction of short test sections of sand seal

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Additional Surveys

GroupSectio

n #

Ride

r #

Mon-198 16 24

SLO-1 3 11

Davis 4 6

Santa

Rosa6 26

Tahoe 4 16

Chico

Velo5 8

Alto Velo 4 16

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MPD(mm)

2 4 6 8

-0.18 0.48

10 15 20 25 30

0.11 -0.70

0.0 0.2 0.4 0.6 0.8 1.0

0.51.01.52.02.53.03.5

-0.68

2

4

6

8

IRI(m/km) 0.56 0 . 0 2 -0.28 -0.30

Vibration Az(g) 0.36 -0.69

0.20.40.60.81.01.21.4

-0.74

10

15

20

25

30

Speed(mph)

- 0 . 0 2 -0.17

Ride Quality(level 1 - 5)

1.01.52.02.53.03.54.04.5

0.92

0.5 1.0 1.5 2.0 2.5 3.0 3.5

0.0

0.2

0.4

0.6

0.8

1.0

0.2 0.6 1.0 1.4 1.0 2.0 3.0 4.0

Acceptability(rate 0 - 1)

Scatterplot Matrix (All Groups)

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RemarksFrom preliminary results, 80% riders rate pavements

with 2.0 mm MPD as acceptable; 50% for 2.5 mm.Sand seal reduces the macrotexture (MPD) of the chip

seal on SLO-1. The final reduction will be measured after completing construction and opening to traffic for a while.

Beside MPD (macrotexture), IRI (roughness/unevenness) may also influence the bicyclist ride quality. Unmaintained pavement develops greater IRI due to cracking, rutting.

Need to consider the balances & tradeoffs:Ride quality (smoothness) and ride safety (skidding

resistance)Vehicle users and bicycle users (different needs)Performance and cost

14http://www.ucprc.ucdavis.edu/PDF/UCPRC-TM-201

3-07.pdf

Final report, including results of additional survey sections, to be completed in December, publish in February.

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Thanks!Q&A

John Harvey, jtharvey@ucdavis.eduHui Li, hili@ucdavis.edu