ROAD MONITORING TO ROAD MONITORING TO PREVENT WEATHER PREVENT WEATHER

PROBLEMSPROBLEMS

Miguel Ángel Rodríguez JaraMiguel Ángel Rodríguez JaraCivil EngineerCivil Engineer

Head of Traffic Control Centre of ValladolidHead of Traffic Control Centre of Valladolid

SUMMARYSUMMARY

• IntroductionIntroduction• System MonitoringSystem Monitoring

• SensorsSensors• Gaps in the data?Gaps in the data?• Correlation between Weather Correlation between Weather

VariablesVariables• The monitor SystemThe monitor System

INTRODUCTIONINTRODUCTION• The prediction of road weather conditions requires the The prediction of road weather conditions requires the

production of accurate forecasts of temperature, humidity production of accurate forecasts of temperature, humidity and precipitation at the road surface.and precipitation at the road surface.

• It is a big challenge to obtain sufficient forecast accuracy of It is a big challenge to obtain sufficient forecast accuracy of the road weather in order to produce correct warnings on the road weather in order to produce correct warnings on slippery road conditions.slippery road conditions.

• The Valladolid TCC is located in way between Portugal, The Valladolid TCC is located in way between Portugal, Basque Country and France. Owing to the location, orography Basque Country and France. Owing to the location, orography and height have a special characteristics that makes the area and height have a special characteristics that makes the area prone to low temperatures.prone to low temperatures.

• The last winter, the area of Valladolid suffered snow problems The last winter, the area of Valladolid suffered snow problems in a set of roads.in a set of roads.

• It Covers four national corridors and two main international It Covers four national corridors and two main international corridors:corridors:• Portuguese CorridorPortuguese Corridor• Magrebian CorridorMagrebian Corridor

INTRODUCTIONINTRODUCTION

International

National

Corridors

SYSTEM MONITORINGSYSTEM MONITORING

• The objectives of this system are to The objectives of this system are to monitor the Roads covered by the TCC of monitor the Roads covered by the TCC of Valladolid and create a software tool to Valladolid and create a software tool to evaluate the progress of the variables evaluate the progress of the variables from the weather station sensors.from the weather station sensors.

• The roads covered in this system contain The roads covered in this system contain sensors which measure temperature, sensors which measure temperature, precipitation, relative humidity, wind precipitation, relative humidity, wind speed, pavement temperature, surface speed, pavement temperature, surface condition, and chemical concentration. condition, and chemical concentration.

SensorsSensors• All the weather stations send the values of each sensor to the All the weather stations send the values of each sensor to the

TCC each 15 minutes.TCC each 15 minutes.

Gaps in the data?Gaps in the data?• In case that any of the SEVAC measure equipments In case that any of the SEVAC measure equipments

gets broken or has a temporal communication gets broken or has a temporal communication problem, it is necessary to take into account that problem, it is necessary to take into account that there exist some weather variables that allow there exist some weather variables that allow substituting some fundamental variables, in such a substituting some fundamental variables, in such a way that the systems for generating alerts and way that the systems for generating alerts and notices and the aid decision system of the Traffic notices and the aid decision system of the Traffic Management Centre are guaranteed. Management Centre are guaranteed.

• Such secondary weather variables are the Such secondary weather variables are the following ones: Visibility and Air Temperature, following ones: Visibility and Air Temperature, which can substitute the fundamental variables: which can substitute the fundamental variables: Rain IntensityRain Intensity (mm/h) and (mm/h) and Surface TemperatureSurface Temperature, , respectively.respectively.

0 1 32

2000

1500

1000

500

4 5 6 7 8Rain Intensity (mm/h)

Vis

ibil

ity

(m)

Correlation between Weather Correlation between Weather VariablesVariables

• The weather variable that The weather variable that allows appreciating the allows appreciating the “Snow Classification” is “Snow Classification” is Rain Intensity. In case that Rain Intensity. In case that there are no rain gauge there are no rain gauge data, the variable to be data, the variable to be used for classifying is used for classifying is Visibility. Visibility.

Rain Intensity (mm/h) Visibility (m)

0 1,800

1 1,600

2 1,400

3 1,200

4 1,000

5 800

6 575

7 375

8 175

Road Safety Risk

Correlation between Weather Correlation between Weather VariablesVariables

• In case that the road detector is broken down In case that the road detector is broken down and, thus, it is not possible to record data about and, thus, it is not possible to record data about the fundamental variable ST (Surface the fundamental variable ST (Surface Temperature), the following correlation with the Temperature), the following correlation with the secondary variable AT (Air Temperature) has secondary variable AT (Air Temperature) has been obtained in the following way: been obtained in the following way:

ST = AT + 1ºCST = AT + 1ºC Su

rf.

Tem

p.

(ºC

)

Air Tem. (ºC)

1 ºC

Correlation between Weather Correlation between Weather VariablesVariables

• The weather variable that allows assessing the The weather variable that allows assessing the “Freezing Effect of the Sun” is the Global “Freezing Effect of the Sun” is the Global Radiation. In the graphic below, it is possible to Radiation. In the graphic below, it is possible to observe how from a radiation superior to 50 observe how from a radiation superior to 50 W/m2, the ST surpasses the W/m2, the ST surpasses the

0 ºC, rising to 1 ºC with an increase of 33 W/m2 0 ºC, rising to 1 ºC with an increase of 33 W/m2 of solar radiation.of solar radiation.

Global Radiation (w/m2)

Su

rf.

Tem

p.

(ºC

) Average 33 w/m≃ 2 / ºC

The Monitor SystemThe Monitor System• The data can be accessed remotely using a The data can be accessed remotely using a

Windows-based software program. The data are Windows-based software program. The data are also stored in a central database for future use.also stored in a central database for future use.

• The accuracy of the system was evaluated The accuracy of the system was evaluated through comparison of atmospheric data with through comparison of atmospheric data with site observations of surface condition, pavement site observations of surface condition, pavement temperature, and air temperature. temperature, and air temperature.

• The reliability was evaluated by reviewing the The reliability was evaluated by reviewing the history log files to located gaps in the data and history log files to located gaps in the data and with the correlation between weather variables. with the correlation between weather variables.

• Problems with individual sensors were also Problems with individual sensors were also documented. The accuracy of the system was documented. The accuracy of the system was found to be good for the sensors that could be found to be good for the sensors that could be directly evaluated. directly evaluated.

The Monitor SystemThe Monitor System

.

.

Each 10 minutes

TCC

Weather Variables Central Server

All Weather stations

PROCESS

Road Operator

The Monitor SystemThe Monitor System

Thanks for your attentionThanks for your attention