Influence of Roadside Environment and Road Structures on - - PowerPoint PPT Presentation

Influence of Roadside Environment and Road Structures on Blowing-Snow-Induced Visibility Hindrance on Winter Roads

: Analysis using the results of weather observations by a visibility

• bservation vehicle during blowing snow.

2016 International Conference & Workshop on Winter Maintenance and Surface Transportation Weather

Civil Engineering Research Institute for Cold Region Hirotaka Takechi, Masaru Matsuzawa, Yasuhiko Ito and Tetsuya Kokubu

Hokkaido Sapporo Tokyo

Outcomes

To clarify the influence of following items on blowing-snow-induced visibility hindrance

Road structures Length of windward flat land Width of roadside tree belt Width of roadside rows of houses Presence/absence of guardrails

 Background and objectives  Method of moving weather observation  Method of multivariate analysis  Results of analysis  Conclusions

Outline

Background

Hokkaido Tokyo

 Winter Road Problems in Hokkaido

Poor visibility and snowdrift caused by snowstorms Traffic hazards

Snowbreak Woods

Background

 It is important to accurately determine which locations are at risk of blowing snow.

Snow fences

 Installation of blowing-snow control facilities to mitigate traffic hazards caused by snowstorms

Objective

The Highway Snowstorm Countermeasure Manual

The Degree of Snowstorm Danger

 It is necessary to develop the technology for risk assessment of snowstorms along entire routes for appropriate installation.

Risk assessment of snowstorms (Image)

 Present technology for risk assessment

• f snowstorms

http://www2.ceri.go.jp/fubuki_manual/index_e.html http://www2.ceri.go.jp/fubuki_manual/pdf/manual.eng.pdf

On The Highway Snowstorm Countermeasure Manual

Snowfall(snow depth)

Road structure Windward flat land Roadside trees and houses

Volume of snow settled at snowdrifts

Frequent

• ccurrence of

blowing snow

ランク 総合評点 判定 A 44点以上 吹雪による障害の危険性が極めて高い B 21-43 吹雪による障害の危険性がある C 1-20 吹雪による障害に対して注意を要する D 0以下 吹雪対策の必要なし

Objective

Snowfall(snow depth)

Roadside trees and houses

 To survey by moving weather

• bservation on winter road

during blowing snow  To clarify the influence of the road environment and structures on blowing-snow- induced visibility hindrance  Items and scores used to assess the degree of snowstorm danger were determined empirically

The degree of Snowstorm Danger

Poor visibility factor Snowdrift factor

Degree of snowstorm danger

Visibility observation vehicle

Moving weather observations were conducted during blowing snow by a visibility observation vehicles.

Method of observation

Visibility, Wind velocity, Wind direction, Air temperature, Latitude and Longitude data

( Sampling interval was 0.1 sec. )

Sonic wind sensor (CLIMATEC,Inc CYG-85004)

Installation height of 2.8m

Forward scattering visibility meter (Meisei. TZF-31A)

Installation height of 1.75m

 Locations of observation

Method of observation

R238 Saroma city, Monbetsu city R232 Enbetsu city, Haboro city R231 Iishikari city R238 Hamatonbetus city, Sarufutsu city

Number of total

• bservation times

2012/12/26 10:49 - 16:23 14.7

• 41.4

9 2013/3/10 15:15 - 18:11 14.2

• 51.7

4 2014/1/13 12:48 - 16:04 14.3

• 51.7

3 2014/1/28 18:26 - 22:15 15.0

• 52.0

5 2014/1/31 14:44 - 17:44 15.0

• 52.0

4 2014/3/6 14:51 - 17:48 17.0

• 26.0

3 2015/2/2 15:13 - 20:05 15.0

• 42.0

8 2015/2/15 10:22 - 18:19 15.0

• 42.0

7 2012/12/27 8:52 - 16:05 35.9

• 76.5

6 2013/2/2 19:49 - 20:26 52.8

• 73.0

1 2013/2/3 8:32 - 9:32 51.8

• 68.5

2 2013/2/5 14:58

• 15:34

44.3

• 70.4

1 2013/2/20 6:32 - 12:51 41.6

• 71.2

7 2014/1/11 11:25 - 15:22 36.0

• 71.4

4 2014/1/28 16:00 - 21:01 35.9

• 71.4

4 2014/1/29 8:50 - 14:11 35.3

• 57.5

5 2014/1/31 17:33 - 18:52 36.0

• 71.4

2 2014/2/3 9:54 - 12:43 36.0

• 64.4

4 2014/3/7 15:44 - 16:43 47.0

• 64.0

2 2015/1/7 15:40 - 21:58 42.0

• 75.0

7 2015/1/8 11:35 - 11:50 71.0

• 81.0

1 2015/3/11 17:20 - 19:58 38.0

• 70.0

2 Route Date of observations KP

※Maximum section

Number of observations Route231 in Ishikari city (KP14.2-52.0) 43 Route 232 from Enbetsu to Haboro city (KP35.3-81.0) 48

 Observation period : Three winters periods of 2012 to 2013, 2013 to 2014, 2014 to 2015

Method of observation

 Date of observations

Number of total

• bservation times

2013/2/8 9:54 - 16:51 63.7

• 102.3

6 2013/3/2 15:05 - 17:23 52.1 - 77.3 1 2014/2/9 17:41 - 23:27 54.6

• 90.2

2 2014/2/17 8:07 - 10:55 74.0 - 102.0 1 2013/1/26 11:40 - 16:11 229.2

• 235.6

8 2013/2/3 12:40 - 15:52 217.9 - 274.3 3 2013/12/27 18:17 - 22:20 217.1 - 258.5 2 2014/1/26 16:10 - 16:41 236.9

• 258.5

1 2014/2/5 5:31 - 5:49 240.0

• 251.9

1 2014/2/10 14:44 - 18:38 219.6

• 257.4

4 2014/2/18 7:50 - 14:18 216.0 - 262.0 6 2015/2/27 8:27 - 20:05 225.0 - 257.0 9 2015/4/15 21:53 - 0:26 222.0 - 258.0 2 Route 238 from Hamatonbetsu to Sarufutsu city (KP216.0-274.3) 36 Route 238 from Saroma to Mombetsu city (KP52.1-102.3) 10 Route Date of observations KP

※Maximum section

Number of observations

Method of observation

 Observation period : Three winters periods of 2012 to 2013, 2013 to 2014, 2014 to 2015  Date of observations

Method of analysis

Data were gathered for each 50-m section of road.

 Average of observed visibility values  Data on road structure, roadside environmental conditions from road inventories, maps, and aerial photographs

Multivariate analysis

 Mathematical quantification theory class I ( Hayashi's quantification method I )

• 1. Response variable

Visibility hindrance occurrence rate (%)

Method of analysis

Number of occurrences

• f avg visibility < 200m

Number of total observation times

×100%

0 Cut of higher than 5.0m 1 Cut of 0-5.0m 2 Fill of 0-1.0m 3 Fill of 1.0-3.0m 4 Fill of 3.0-5.0m 5 Fill of higher than 5.0m 0 N/A 1 10-100m 2 100-300m 3 More than 300m 0 N/A 1 Scarce 2 10～30m 3 30～50m 4 50～100m 5 100～200m 6 200～300m 7 More than 300m 0 N/A 1 Scarce 2 10～30m 3 30～50m 4 50～100m 5 100～200m 6 200～300m 7 More than 300m 0 Absent 1 Present Windward Road structure (Height of cut and fill )

Independent variable

Item

Length of flat land windward Width of tree belt Width of rows of houses Presence/absence guardrails

Category

• 2. Independent variable

Method of analysis

 Road structure  Length of windward flat land  Width of roadside tree belt  Width of roadside rows of houses  Presence/absence of guardrails A road section without blowing-snow control facilities were studied.

Response variable Category score Item range Partial correlation coefficient p-value

0： Cut of higher than 5.0m

• 0.

0.101 101 1. 1.950 950 0.104 6.5×10^-7 1： Cut of 0-5.0m 0. 0.393 393 2： Fill of 0-1.0m

• 0.

0.462 462 3： Fill of 1.0-3.0m

• 0.

0.197 197 ※The rate (%)= 4： Fill of 3.0-5.0m 1. 1.488 488 5： Fill of higher than 5.0m 0. 0.723 723 0： N/A

• 0.

0.547 547 1. 1.681 681 0.114 4.5×10^-8 1： 10-100m 0. 0.087 087 2： 100-300m 1. 1.305 305 3： More than 300m 1. 1.134 134 0： N/A 0. 0.120 120 1. 1.591 591 0.056 7.6×10^-3 1： Scarce

• 0.

0.245 245 2： 10～30m

• 0.

0.166 166 3： 30～50m

• 0.

0.052 052 4： 50～100m

• 0.

0.386 386 5： 100～200m

• 0.

0.790 790 6： 200～300m

• 1.

1.189 189 7： More than 300m

• 1.

1.471 471 0： N/A

• 0.

0.294 294 6. 6.090 090 0.156 4.8×10^-14 1： Scarce 0. 0.933 933 2： 10～30m 1. 1.776 776 3： 30～50m 4. 4.412 412 4： 50～100m 1. 1.760 760 5： 100～200m 0. 0.206 206 6： 200～300m

• 0.

0.363 363 7： More than 300m

• 1.

1.677 677 0： Absent

• 0.

0.375 375 1. 1.532 532 0.118 1.3×10^-8 1： Present 1. 1.157 157 2. 2.761 761

Independent variable ( Item and category )

Road structure (Height of cut and fill ) Length of windward flat land

Visibility hindrance

• ccurrence rate (%)

Width of windward tree belt Width of windward rows of houses Presence/absence of guardrails

Constant

Number of occurrences

• f avg visibilty < 200m

Number of total observation times ×100%

Results of analysis

• 2
• 1

1 2 3 4 5

Cut of higher than 5.0m Cut of 0-5.0m Fill of 0-1.0m Fill of 1.0-3.0m Fill of 3.0-5.0m Fill of higher than 5.0m N/A 10-100m 100-300m More than 300m N/A Scarce 10～30m 30～50m 50～100m 100～200m 200～300m More than 300m N/A Scarce 10～30m 30～50m 50～100m 100～200m 200～300m More than 300m Absent Present Road structure (Height of cut and fill ) Length of windward flat land Width of windward tree belt Width of windward rows of houses G C

Categor egory S y Score

Guardrails Constant

Category for each item

 Category score of each item

Results of analysis

• 2
• 1

1 2 3 4 5

Cut of higher than 5.0m Cut of 0-5.0m Fill of 0-1.0m Fill of 1.0-3.0m Fill of 3.0-5.0m Fill of higher than 5.0m N/A 10-100m 100-300m More than 300m N/A Scarce 10～30m 30～50m 50～100m 100～200m 200～300m More than 300m N/A Scarce 10～30m 30～50m 50～100m 100～200m 200～300m More than 300m Absent Present Road structure (Height of cut and fill ) Length of windward flat land Width of windward tree belt Width of windward rows of houses G C

Categor egory S y Score

Guardrails Constant

Ｘ

 Category score of each item

Results of analysis

Category for each item

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

Height of cut and fill Length of windward flat land Width of windward tree belt Width of windward rows of houses Presence/absence

• f guardrails

It Item r m rang nge

Results of analysis

Item

 Range of category score of each item

 The visibility hindrance occurrence rate during blowing snow tended to be high for roads with long windward flat land. With flat land of 100 m or longer, the rate tended to be high.  On roads with a windward tree belt of 100 m or wider or with rows of houses of 300 m or wider, the rate tended to be remarkably low. The visibility tended to be good at such locations.  The rate tended to be high at fills of about 3 m or higher and at cuts of lower than 5 m.  At sections with guardrails, the rate tended to be higher than at road sections without guardrails.

Conclusions

Thank you for your kind attention

For more information, question snow@ceri.go.jp hiro-takechi@ceri.go.jp Snow and Ice Research Team Civil Eng. Res. Institute for Cold Region