System and method for weather mapping to road segments

A computer-implemented method for generating a weather index mapped to a road segment for a particular time frame includes receiving weather condition information for a plurality of time periods, parsing the weather condition information to determine weather conditions for a road segment defined by a starting point and an ending point for the plurality of time periods, and generating a plurality of weather indices for the road segment. Each weather index is associated with one of the plurality of time periods and is representative of a predicted traffic impact based on historical information of the received weather conditions for the road segment. The plurality of time periods includes at least one future time period and the weather condition information includes forecasted weather information.

FIELD OF THE INVENTION

The present invention pertains generally to systems and methods for generating weather and traffic information and for presenting weather and traffic reports and forecasts and the like, and, more specifically, to systems and methods for providing past, current, and forecast weather condition information for use in traffic forecasting, route navigation, traffic flow, and routing, and more particularly, to the generation of information and indexes for specific road segments based on past, present, and future weather conditions.

BACKGROUND OF THE INVENTION

Weather is one of the most significant conditions that affect how people and goods get from one location to another. The ability to easily make travel decisions based on weather conditions is important for saving both time and money. The current methods for making these weather decisions for specific road segments requires the collection of a wide variety of weather sources that can be widely dispersed and which have no specific correlation with a segment of road. In addition, the weather data does not include any value added indexing that helps in the decision making on movement along that road segment. Embodiments of the present invention are designed to provide road segment specific weather indexing and information in a format that is easier to use in third party systems that are making decisions on travel and routing.

Traffic and weather go together. Traffic and weather represent two of the most practical categories of information and news that many individuals use almost every day in planning and living their lives. Thus, it makes sense that traffic and weather information are most often provided together, side by side. For example, drive-time radio will often provide a traffic report, followed immediately by a weather report, or vice versa, to listening commuters several times an hour. Similarly, on-line services will offer or present traffic and weather reports in close proximity, e.g., on a website offered by the same provider. Thus, for example, on a general news or information website one will typically find the links for traffic and weather reports close together, or even right next to each other.

Besides their common importance in people's lives, traffic and weather also go together in another sense. It is well known that weather is an important component in determining traffic flow along roadways. Weather conditions, particularly severe weather conditions, often can affect traffic conditions. Normal traffic conditions and drive times can be affected significantly by severe weather conditions such as heavy rain, snow, ice, and the like.

Thus, weather conditions must be taken into account in order to model accurately traffic conditions. For example, TrafficCast of Madison, Wis., employs forecast weather condition information in combination with historical traffic data to provide an accurate model of traffic conditions that may be used to predict traffic conditions on specific routes at specific points in time in the future. Using historical traffic data for particular travel routes in combination with current or predicted traffic affecting weather conditions and other data an accurate forecast of traffic conditions along a route may be obtained. For example, by analyzing historic traffic conditions, a model of travel times along a section of roadway may be obtained for, for example, particular days, days of the week, seasons of the year, times of day, etc. By analyzing such historic traffic data along with the historic weather data, the effect of various weather conditions on traffic conditions also may be determined and included in the traffic forecast model. Using such a model based on historic traffic and weather information, along with known or predicted future conditions, e.g., predicted weather conditions from a weather forecast model, a forecast of traffic conditions, e.g., travel times, along a roadway may be determined. Such a traffic forecast may be included as part of a traffic report that is provided to users, e.g., via the internet, any portable or otherwise personally addressable communication device, radio or television broadcast, etc.

The weather information employed by the TrafficCast traffic models is provided by MyWeather LLC of Madison, Wis., in a form that is specific to the TrafficCast traffic models. Specifically, for this purpose, a geographic area having various traffic routes of interest to be modeled is divided into a grid. Weather products are generated for each grid area by MyWeather and provided to TrafficCast for use in the TrafficCast traffic forecast models. For example, the weather products for each grid area include weather forecast information generated by MyWeather using a weather forecasting model, such as the ADONIS Microcast weather model, available from Weather Central Inc. of Madison, Wis. The ADONIS Microcast model is a sophisticated computer implemented weather forecasting model that employs information on current weather conditions as initial conditions. Such a weather forecasting model is able to generate detailed predictions of various weather conditions (e.g., temperature, precipitation, wind speed, severe weather conditions, etc.) having a high degree of geographic and temporal resolution and with significant accuracy. Such high resolution forecast weather condition information may then be used to provide forecast weather information for each geographic grid area that is then used by the TrafficCast traffic forecast model to generate accurate traffic forecasts for the various modeled traffic routes that pass through the grid areas.

Thus, although it is known to use weather information in traffic forecast modeling, to date weather information used for such a purpose has been generated and formatted specifically for particular traffic forecast model applications. Weather information has not generally been made available in a form that is useful generically for traffic forecasting or for use in other traffic related products and services, such as navigation, traffic flow and routing. Specifically, the common denominator in traffic flow and routing analysis is the road segment, not a geographic grid area. What is desired, therefore, is a system and method for generating and providing weather information that is specific for specific road segments and which, therefore, will be readily useful for enhanced traffic flow, routing, and navigation generation. Such a system and method preferably provides weather information in the form of one or more numerical or other index values for a plurality of road segments and for a plurality of time periods. Thus, users of such a system or method, or applications using the information provided thereby, can readily determine weather effects at particular road segments at specific points in time for a variety of applications, such as traffic routing.

BRIEF SUMMARY OF THE INVENTION

The common denominator in traffic flow and routing is the use of road segments. Each route to be considered may consist of thousands of such road segments. The condition of traffic flow on these road segments is the usual output of any traffic sensor or modeling system. Like road segment flow information, embodiments of the present invention provide weather indexes for each road segment for a plurality of time periods (past, present, and/or future) using a number of historic real-time and forecast variables. This mapped weather data may then be used by various traffic and mapping companies or applications to help calculate traffic flow, determine alternative routing, and make fleet management decisions.

Embodiments of the present invention provide a system and method for providing historical, real time and forecast weather information that is mapped to defined road segments for a series of time periods. Such mapped weather data will be useful specifically as an input to systems and methods for traffic analysis and forecasting including navigation, traffic flow, and routing. A system for mapping weather data to road segments in accordance with one embodiment of the present invention may be implemented for substantially automatic operation in a conventional computer system. Weather information from historic data (climatological averages, trends), real-time (weather radar, satellite, weather sensors, government weather alerts) and forecast (weather forecast model) weather information sources is provided to the computer system. Road segments, typically defined by specific geographic end point locations, are provided in a road segment database or otherwise provided to the computer system.

Using weather mapping software implemented in the computer system, a system and method in accordance with some embodiments of the present invention generates weather indexes for various historic, real-time, and forecast weather conditions for a plurality of time periods for each desired road segment by appropriate extraction of the desired weather information from the weather information provided to the system from the various weather information sources and processing of the extracted weather information using appropriate weights and thresholds. For example, with real-time weather radar data, storm cell tracking, and rain/snow/mix masking, a system and method in accordance with one embodiment of the present invention may be used to provide weather indexes for the road segments being affected by precipitation for a plurality of time periods. The use of a weather forecasting model, such as Microcast, provides the ability for a system and method in accordance with an embodiment of the present invention to forecast various weather indexes for road segments for a series of times in the future. A summary weather index representing the total impact of weather on a road segment at a particular point in time (past, present, or future) may also be generated.

The resulting weather data mapped to road segments for a series of times may then be stored in an appropriate database and/or provided to another application in the form of a multi-dimensional data structure or table of road segments, time periods, and one or more weather indexes for each road segment time period. Such mapped weather data may be used, either manually or by automated systems for, for example, automated navigation, traffic flow and routing, and the like. The mapped weather data may be updated frequently as needed by repeating the process as new weather information is received from the weather information sources.

According to one exemplary embodiment, a computer-implemented method for generating a weather index mapped to a road segment for a particular time frame includes receiving weather condition information for a plurality of time periods, parsing the weather condition information to determine weather conditions for a road segment defined by a starting point and an ending point for the plurality of time periods, and generating a plurality of weather indices for the road segment. Each weather index is associated with one of the plurality of time periods and is representative of a predicted traffic impact based on historical information of the received weather conditions for the road segment. The plurality of time periods includes at least one future time period and the weather condition information includes forecasted weather information.

Thus, embodiments of the present invention provide a highly useful data source of weather information for any type of route planning, fleet management systems and forecasted flow calculations. Mapping weather data to road segments in the form of indexes for specific times is a feature of the present invention that makes such weather data easy to use and valuable as a data product for such potential traffic related applications.

DETAILED DESCRIPTION OF THE INVENTION

An exemplary system10for mapping weather data to road segments in accordance with the present invention will be described in detail with reference toFIG. 1. A system10for mapping weather data to road segments in accordance with an embodiment of the present invention preferably is implemented in software running on a conventional computer system12. The computer system12may be a single computer or multiple computers coupled together via a conventional network for operation together in a conventional manner. The computer system12preferably is provided with conventional input14(keyboard, mouse, etc.) and output16(monitor, printer) or display devices to allow an operator of the system10to interact therewith in a conventional manner.

The computer system12is preferably also provided with memory17which may be provided in the form of one or more conventional memory devices (e.g., ROM, RAM, disc storage, etc.). Such memory17preferably contains weather mapping software18which is run on the computer system12to perform the functions of mapping weather data to road segments in accordance with the present invention, as described in further detail herein. Memory17also may contain summary weather index generation software19which is run on the computer system12to generate a summary (or severity or impact) index for a series of time periods for the road segments based on the weather mapped to the road segments, as also described in further detail herein. Conventional software applications necessary or desirable for the general operation of the computer system12(such as operating system software, networking software, database software, etc.) may also be provided in memory17. With reference to the detailed written description and functional flow chart diagrams provided herein a person of ordinary skill in the art of computer programming for weather related applications will be able to implement a method for mapping weather data to road segments in accordance with the present invention on a conventional computer system using conventional operating systems and programming languages.

In accordance with an embodiment of the present invention, weather information is provided to the system10from various weather information sources20. Such weather information sources20preferably may include historic archived or climatological weather data21, real-time or generally current weather information sources, such as weather radar22, weather satellite24, and weather sensor26sources, as well as forecast weather information sources, such as from weather models28, and weather warnings and/or alerts29from government or other providers, such as the National Weather Service. Other or different weather information sources, such as real-time lightning strike data information sources, also, or alternatively, may be used to provide weather information to the system10. The desired weather information sources20employed will depend upon the desired weather information indexes to be provided for the road segments, as will be discussed in more detail below. Each weather information source20may provide its particular weather information in a specific format and using specific protocols.

Historic weather data21may include weather data from the real-time or generally current weather information sources (e.g., radar22, satellite24, and/or weather sensor26information) that is received by the system12and appropriately time stamped and archived as historic weather data21. Historic weather data21may also include historic archived weather data and/or climatological weather data from external sources of such data.

Weather radar data provided to the system10from weather radar sources22may include data from live local weather radars and/or weather data provided from government weather radar sources, such as the National Weather Service NEXRAD weather radar system. Weather radar from local weather radars is substantially real-time. NEXRAD weather radar data provides much more detailed and processed weather radar information products, but is delayed from real-time by about six minutes.

Weather sensor weather information data sources26include automated and manned weather stations and devices that provide a variety of general weather information (temperature, precipitation, wind speed and direction, etc.) at specific geographic locations and points in time. Such information may be provided automatically and continuously to the system10from the weather sensors26via an appropriate remote connection and/or manually input to the system10, e.g., by remote weather observers via an internet or other connection to the system10.

Forecast weather information is preferably provided by one or more weather models28providing a variety of forecast weather condition data (e.g., temperature, precipitation, wind, etc.) at a high degree of both geographic and temporal resolution. The ADONIS Microcast model described above is an example of such a weather forecast model. The weather forecast model28may be run, in whole or in part, on the computer system12that is used to implement weather data mapping to road segments in accordance with an embodiment of the present invention. Alternatively, output from a weather forecast model28run on a different computer may be provided to the system computer12.

As illustrated inFIG. 2, routes38used in traffic flow and routing, navigation, and other traffic related applications, are typically defined in terms of the road segments38.1,38.2,38.3, etc. that together comprise the route38. (Although only a few road segments are shown to comprise the exemplary route38inFIG. 2, it should be understood that a typical route used in many traffic related applications may consist of thousands of road segments.) Typically individual road segments that define a route38may be of unequal length and are generally defined in geographic space by the lat/lon of each of the end points (the start and end points) of the road segment.

Returning toFIG. 1, the large plurality of road segments that define a plurality of routes may be stored in a road segment database30that is accessible by the computer system12. For example, the road segment database30may include a plurality (perhaps thousands of lat/lon pairs that define road segments for a plurality of routes and/geographic areas. The road segment database30may be part of a system10for weather data mapping in accordance with an embodiment of the present invention. Alternatively, the road segment database30may be held and maintained outside of the system10, e.g., by a provider or application that provides traffic flow and routing, or the like. In the latter case, the road segment definition data defining road segments for which weather data is to be mapped in accordance with an embodiment of the present invention may be provided to the system10by the outside source at the appropriate time via any appropriate network connection31.

A geographic database32may preferably be employed to facilitate the process of extracting and processing weather information from the various weather information sources20for mapping to road segments in accordance with an embodiment of the present invention. The geographic database32may contain general geographic information necessary for converting weather information provided from the weather information sources20into a lat/lon format preferred for mapping such weather information to the road segments. For example, a weather alert from a government weather alert source29may indicate that there is severe weather in a particular county. Geographic information in the geographic database32may be used to determine the range of lat/lon locations that comprise the referenced county in order to determine which road segments (defined by lat/lon) are located in the affected county.

A weights and thresholds database33contains weights and thresholds that are used by the system10, in a manner to be described in more detail below, to generate weather indexes for specific points in time for various road segments from the weather information that is mapped to road segments by the system. In general, the weights and thresholds in the database33are used to translate mapped weather data into numerical or other indexes that represent various weather conditions at the road segments at various points in time. The weights and thresholds33used may be selected based on the ultimate use of the indexes to be generated by the system10in accordance with an embodiment of the present invention. For example, if the indexes are to be used for traffic flow and routing, the weights and thresholds used may be selected, based on empirical research, to translate accurately specific weather conditions to a numerical or other value that represents the effect of such weather conditions on traffic flow.

Time stamped weather data that is mapped to road segments in accordance with an embodiment of the present invention may be stored in an appropriate database34for later use, or sent immediately or at an appropriate time, by any appropriate network connection31, to an outside application or provider. Thus, use of the weather mapped to road segments in accordance with an embodiment of the present invention for traffic flow and routing, navigation, and the like may be made either inside or outside of the system10.

An exemplary method for mapping time stamped weather data to road segments in accordance with an embodiment of the present invention will now be described in detail with reference toFIG. 3. The mapping process18may be started40manually, periodically at desired user selectable intervals or times, or in response to an event trigger. Exemplary event triggers may include a request from an outside provider or application for an update of mapped data or the occurrence of specified changes in the weather information provided by one or more of the weather information sources20(e.g., the issuing of a new weather alert29or the detection by weather radar22of a new storm cell).

After starting40the process road segment data for a first road segment is retrieved42from the road segment database30. As described above, the road segment data in the road segment database30may be provided and maintained either locally or remotely. The retrieved42road segment data may include, for example, the lat/lon end points that define the road segment.

A weather index is then determined for the road segment at44and45. The weather index to be determined may be a historic weather index, a real-time or current weather index or a forecast weather index and is time stamped for a particular appropriate point in time (past, present or future) as the case may be. Exemplary real-time or current indexes for road segments that may be determined in accordance with an embodiment of the present invention may preferably include precipitation type (rain, mix, snow, etc.), precipitation intensity (dbz levels), precipitation accumulation (QPF), hail potential, tornado potential, storm cell arrival, storm cell attributes (hail, wind, TVS, MESO), etc. Forecast weather indexes for road segments that may be determined in accordance with an embodiment of the present invention may preferably include precipitation type, precipitation amounts, wind speed, precipitation accumulation, fog, temperature, etc.

The process used to determine a particular weather index for a road segment may be implemented in two basic steps. First, it is determined44, based on weather information from the weather information sources20whether or not a particular type of weather affects the road segment at a specific time period and the specific characteristics of that weather at that road segment and time period. Such characteristics may depend upon the types of weather being considered, and may include such characteristics as an indication of weather intensity or size, severity, direction, probability of occurrence, etc. Second, based on the weather determined44to affect the road segment and the weights and thresholds from the weights and thresholds database33a numerical weather index is determined45. Each of these basic steps44and45will now be described in more detail.

The process of determining44the weather affecting the road segment will depend upon the weather information source20and the form that the weather information is provided in from that source20for the particular weather index to be determined. The process used to determine44the weather affecting the road segment may make use of the geographic information from the geographic information database32, as needed. Several examples of such processes follow, but others will be known to those skilled in the art.

To determine storm cell arrival at a particular road segment, storm cell60characteristics (e.g., wind speed, precipitation intensity, etc), location and speed and direction of movement information may be retrieved from a weather radar source22. From this information a wedge shaped path62of predicted storm movement may be generated in a conventional and well known manner. (SeeFIG. 2.) The system10may then determine storm cell arrival by determining, for example, if either end point lat/lon of the road segment of interest is within the predicted storm path and62, if so, determining the estimated storm arrival time at the lat/lon of the closest of the two road segment end points to the current storm cell location, using current detected storm speed and location. The result based on estimated storm arrival time and duration is an indication of the predicted storm conditions at the road segment for a series of time periods.

Most weather forecast models28provide weather forecast information for various types of weather for a series of future time intervals (e.g., one-half hour apart) for geographic grid locations64. (SeeFIG. 2.) In such a case, determining44the forecast weather for a road segment requires determining in which modeled geographic grid areas the road segment is found. Since road segments of interest may cross modeled grid area borders, the system10preferably determines how best to extract and process model grid weather data to be mapped to a road segment. This may include using only model grid data for the geographic grid in which the largest portion of a road segment is found. Alternatively, the mapped forecast weather may be derived from modeled weather information for each modeled grid area through which a road segment passes, and may be weighted based on the portion of the entire road segment that is found in each relevant grid area.

Having determined44if a particular type of weather affects a road segment at a particular time, a numerical or other index for that weather type for the road segment for a particular time period is determined45using the determined44weather characteristics and weights and/or threshold from the weights and thresholds database33. (As discussed above, the weights and thresholds33may be predetermined with particular reference to the effect of various types of weather on road travel.) For example, precipitation may be indexed on a scale of 1 to 10 (of course any quantitative or qualitative scale may be used) with a precipitation index of 1 corresponding to no precipitation and a precipitation index of 10 corresponding to very intense precipitation. The weights and thresholds33are used, in this case, to translate the determined44precipitation affecting the road segment into an index number between 1 and 10. Similar or different scales and procedures may be used to create indexes of this type for other types of weather determined to affect the road segment. The resulting weather indexes are very easily adaptable and useable by third party systems, (e.g., for traffic reporting, prediction, routing, etc.) involving the road segment.

After determining45a weather index for a particular road segment and time period, the determined index is mapped46to the road segment and the updated mapped data is stored in the mapped weather database34.

The mapped weather index includes a time stamp indicating the time (past, present or future) for which the particular mapped index applies to the road segment. This process may then be repeated47for a series of time periods, as desired. (E.g., for calculating indexes based on modeled weather data28for a series of half hour periods into the future.) If another weather index48is to be determined or updated for a particular road segment the determining process44and45is executed again, perhaps using weather information from another weather information source20and a completely different weather index extraction and determination process.

A summary weather severity or impact index may be determined49for a road segment. The summary weather index may take the form of a single number or other indication that indicates the total weather impact (e.g., on traffic) at a particular time (or series of times) for a particular road segment. The summary weather index may be generated based on all of (or a subset of) the weather indexes or other weather information mapped to a road segment for a particular point in time (or including a series of time points) and appropriate weights and thresholds from the weights and thresholds database33. For example, a road segment affected by light rain and very high winds may receive a summary weather index of 3 on a scale of 1 (little weather impact) to 10 (high weather impact). A road segment affected by heavy snow, no wind, but rising temperatures (chance of snow turning to rain) may receive a summary weather index of 8 on such a scale. Different scales, of course, may be used, and the actual index calculated will depend on the weights and thresholds33applied. The resulting summary index (for a particular time or series of times) is saved along with the other mapped weather indexes34. Such a summary index may be used by certain third party systems and providers that need, or desire, a general indication of the weather effect at a particular road segment (e.g., for traffic prediction, routing, etc.).

The entire process being described may be repeated50for each road segment in the road segment database30for which weather indexes are to be calculated or updated.

The result of the process being described is a multi-dimensional table or other data structure comprising a series of road segments, a series of time periods associated with each road segment and one or more weather index values for each road segment/time period. As discussed above, a weather index determined in accordance with an embodiment of the present invention may be quantitative (e.g., a number) or qualitative (e.g., “high”, “medium”, “low”, etc.) as required or desired by the end user of the data.

At the appropriate time, the mapped weather data34generated in this manner may be transmitted52, e.g., via the network connection31, to another process or location for use in determining traffic flow, routing, and the like. Such a transmission may be in real-time, or near real-time, as the mapped weather data for each road segment is updated, or in batch mode from the mapped weather data database34. The process ends54with the weather data mapped to road segments in accordance with an embodiment of the present invention stored and/or transmitted for use.

Mapped weather indexes in accordance with an embodiment of the present invention may be made available for general use or tailored for user specific applications. For example, mapped weather data including a variety of different weather indexes may be made generally available for use as needed by specific users. Thus, a county highway department may access such mapped weather data to view predicted snow accumulation indexes for road segments in a county of interest. The department may thus quickly determine which road segments will become snow covered at what times and thus position snow clearing equipment for best effectiveness based on such information. By using weights and thresholds specifically tailored to a user application, mapped weather data in accordance with an embodiment of the present invention may be employed to enhance the effectiveness of applications such as sophisticated route planning software. For example, a traveler may enter start and end points for a route as well as a starting or arrival time into such a system. The system may then calculate the quickest route, taking into account not only static information (road segment distances) but also travel weather conditions at specific road segments at specific times as provided by a system and method in accordance with an embodiment of the present invention.

It should be understood that the present invention is not limited to the particular exemplary applications and embodiments illustrated and described herein. In particular, the individual functions of mapping weather data to road segments as described with reference toFIG. 3may be implemented in a different manner and order from that described by example herein.