Drivers’ decision-making supported by The Snow Visibility Information system Kokubu, T bu, T., , Takec echi hi, H H., ., Har arad ada, Y., Om ., Omiya, S S., and M ., and Mats atsuzawa, M M Civil E Engi gineer neering R ng Resear earch I h Institut ute f e for C Cold R d Region ( on (CERI), ), P PWRI, , Japan an
Introduction Hokkaido is the northernmost island of Japan. Hokkaido Sapporo, CERI Max:208cm=6ft9in Jan 30, 2012 Iwamizawa 30km (19miles), NE. of Sapporo [ 2 ]
Background Flood Bank collapsed 1% Eruption Risk of road flooded 1% Snowfall High wave Road flooded Snowstorms cause ... National road closure in Hokkaido Snowstorm Risk of landslide 1998 - 2007 Total ; 2020 times Poor visibility Winter Landslide Avalanche Risk of avalanche Summer 5% Causes of national road closure in Hokkaido Snowdrifts * 40% of road closures - snowstorms [ 3 ]
Background Reduce damage caused by snowstorms ... Snow break woods Road: Installation of blowing-snow control measures Driver: Help drivers to make safer decisions Snowstorm visibility information Snowstorm Information Blowing-snow control facilities Chose safer route Visibility Information Snow fences * Control measures are installed in areas storms frequently occur. * Recently, bomb cyclones cause blowing-snow. * Snow-control facilities require much time and cost to construct, [ 4 ] so cannot address sudden storms.
Objectives “Northern Road Navi” Website” - Portal Site for Road in Hokkaido - Hokkaido Road Information Website Contents • What’s New • Distance & Time • Mountain Pass / Live Camera • Road Map • Links to Weather Info + Snowstorm visibility infomation URL: http://northern-road.jp/navi/ [ 5 ]
Method of estimating visibility during snowstorms Relationship between visibility during snowstorms and the mass flux of snow ……… (1) (Takechi, 2009) Vis [m] : Visibility Mf [g/m 2 /s] : Mass flux of snow The mass flux of snow is the mass of snow particles snow particles passing through a specific unit cross-section during a particular unit time [ 6 ]
Method of estimating visibility during snowstorms Relationship between the mass flux of snow and the snow concentration …………(2) Mf [g/m 2 /s] : Mass flux of snow N [g/m 3 ] : Snow concentration The snow concentration is the mass of snow particles in a particular unit space V [m/s] : Wind velocity Wind velocity Mass Flux of snow Snow Concentration [ 7 ]
Method of estimating visibility during snowstorms Method of estimating the snow concentration Estimation using snowfall intensity, wind velocity and air temperature …………(3) (Matsuzawa et al,1998) Snowfall Drifting snow P [g/(m 2 s)] : Snowfall intensity w f [m/s] : Falling velocity of snowfall particles ( = 1.2 [m/s]) w b [m/s] : Falling velocity of suspended snow particles ( = 0.35 [m/s]) z [m] : Height of the viewpoint of small-vehicle drivers ( = 1.2 [m]) z t [m] : Reference height (0.15 [m]) : When snowfall intensity is high. N t = 0.166 ・ e0.309 ・ V 10 N t [g] When snowfall intensity is low or zero N t = 0.274 ・ e0.401 ・ V 10 (Where, V 10 is the wind velocity at a height of 10 m) U * : Friction velocity ( = 0.036 × V 10 ) K : Karman’s constant ( = 0.4) [ 8 ]
Method of estimating visibility during snowstorms Judgment of visibility conditions In providing the information, to facilitate understanding of visibility during snowstorms, the estimated visibility was classified into five levels ranging from 1,000 m or more to less than 100 m. [ 9 ]
Snowstorm Visibility Information System Snowstorm Visibility Snowstorm Visibility Information for PCs Information for smart phone 24 hour later As of March 10 2015,15:00(It’s renew 30minitues) Wakkanai Forecast Abashiri Rumoi Good Good (1,000m or more) (1,000m or more) Asahikawa Somewhat poor Otaru (500-999m) Poor Sapporo (200m-499m) Kushiro Quite poor (100-199m) Muroran Significantly poor (less than 100m) Hakodate Area: 221 areas in Hokkaido [ 10 ]
E-mail delivery service Conditions for Automatic E-mail Delivery Receive e-mails informing of poor visibility forecasts R eduction of visibility in the Nemuro north area 200 m is expected over the next 6 hours due to snowstrom. Please monition conditions and consider you safely 2015 15/0 /01/ 1/09 09 06:01 01:12 12 when driving during his period. fuyumichi@time-n-rd.jp ( xxsampleaddressxx@ceri.go.jp ) Nemuro north area 6 o’clock ： Reduction in visibility range Nakashibetsu town 1hour delay ： visibility less than 100m □ less than 500m Reduction of visibility in the nemuro north area 200 m is expected over the next 6 hours due to □ less than 200m snowstrom. Shibecha town 1hour delay ： Please monition conditions and consider you □ less than 100m safely when driving during his period visibility less than 100m INemuro north area Nakashibetsu town 1hour delya ： visibility less than 100m ： Shibecha town 1hour delya ： visibility less than 100m ： ↓↓ for details ↓↓ ： ↓↓ for details ↓↓ PC web site For PC website http://northern-road.jp/navi/touge/fubuki.htm □ 3hours http://northern-road.jp/navi/touge/fubuki.htm □ 6hours ： [ 11 ]
The number of visitors to the Snowstorm Visibility Information Website ( this winter ) Cumulative page views (PC and smartphone) MAX ： 30,547views 30,000 The Japan Meteorological Agency announced that the snowstorm would be on a scale of that occurring only Page views per day once in several years. 20,000 Mean for Nov. 28 through Mar. 31 4,154 views per day 10,000 0 December March January February November [ 12 ]
Users questionnaire. Implemental method: questionnaire is the home page. Period of the execution: 2015. 4.21 ～ 5.20 The number of respondents: number of 483 [ 13 ]
Users questionnaire. Aim of a questionnaire survey: Of the user, to grasp the Utilization of snowstorm visibility information. And, we want to clarify the validity. We wants to clear the future problem. - Website service - satisfaction - change is doing plane - E-mail service - satisfaction - behavir change planning answers [ 14 ]
The attribute of the questionnaire respondent The age composition The main use purpose 20 Year Old More than 70 Generation, 3% years old , 3% Other, 4% 60 Year Old 30 Year Old Go to hospital Generation, Generation, Commuting, 13% and shopping, 13% 21% 16% Work （ transport ） , Traveling, 17% 50 Year Old 6% 40 Year Old Generation, Generation, Work （ road 33% 35% Work management ） , （ other ） , 10% 26% 63 ％ 81 ％ Respondents: 429 Respondents: 473 Respondents: 473 [ 15 ]
Questionnaire survey results on the usefulness of visibility forecast information provided How satisfied are you with the services provided by the Snowstorm Visibility Information System? Website for smartphones Website for PCs Dissatisfied 2% Very dissatisfied 0% Dissatisfied 4% Very dissatisfied Website for smartphones Somewhat 0% Very Somewhat Very dissatisfied 10% satisfied dissatisfied 10% satisfied 13% 11% Somewhat Somewhat satisfied Satisfied satisfied 29% Satisfied 32% 46% 43% 90 ％ 88 ％ Respondents: 263 Respondents: 259 [ 16 ]
Questionnaire survey results on almost Change behavior visibility forecast information provided How likely is it for you to change your schedule or travel plans when poor visibility of less than 200 m is predicted by the Snowstorm Visibility Information System? Poor visibility of 200 m or less has never been predicted Breakdown in the forecast area. 3% I always or often keep my travel I changed my departure 60% plans or schedule unchanged. time. 19% I refrained from going out 59% or traveling. I always or often change my 40% I changed my route. travel plans or schedule. 79% I brought a shovel and 22% warm clothing. Respondents: 448 I canceled my driving plans 7% and used public transport. 4% Other 0% 20% 40% 60% 80% Multiple answers ( Respondents 352) Excluding two respondents who gave no answers [ 17 ]
Segmenting for carrying out a cross-tabulation We do cross-tabulation of the questionnaire. z The attributes of the respondents I be classified as follows. Other, 4% Use classification for cross-tabulation classification Purpose of the questionnaire Go to hospital Commuting Commuting Commuting, and shopping, 21% 16% Work （ transport ） Work Work Work （ transport ） , （ road management ） Traveling, 17% 6% Work （ other ） Work （ road Work Traveling Private management ） , （ other ） , Going out shopping and go 10% 26% to hospital Other Respondents: 429 [ 18 ]
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