A road map is a depiction of the major roadways in a medium to large area. Generally, interstate highways are displayed in a brighter color than other roadways.
At the Thruway Authority, our GIS group uses bi-directional route systems to display information. This avoids positional inaccuracies that may occur when restricting data events to fall only on the centerline highway.
Roadways
There are countless types of roads on the planet. There are dirt roads that traverse vast deserts and massive mountain ranges, and there are eight-lane expressways that zip through bustling cities. Each road serves a different purpose, and the roadways on a free highway maps reflect this.
A road map can be used to navigate a region from one city to another, or it can be used to identify major routes within a larger metropolitan area or a state. These maps can be purchased at gas stations, airports, rest areas and other locations. They are typically available for a small fee, or they can be free.
An interstate highway is distinguished by a bright red solid line and an interstate shield label symbol. This type of highway is a high-speed, controlled-access road that provides for major traffic movement between centres of population and economic activity on a national or regional basis. Other highways include limited-access highways and principal roads. Principal arterials are major roads that serve a variety of traffic movements on a local basis. These roads connect between other arterials, township streets and residential streets within a neighbourhood.
Frontage roads should be set to at least the Primary Street road type if they are not marked as a higher class on a functional classification map. These roads are often the only way to enter and exit a freeway, and they can cause routing problems if they are set to Street. In certain situations, roads that are not intended for general traffic but which are frequented by vehicles such as service trucks may be mapped using the Runway road type provided they remain disconnected from any runway.
Speed Limits
If you’re a driver, it is important to be aware of the speed limit on each road you travel on so that you don’t accidentally get pulled over for speeding. Google Maps has a useful feature that displays the current speed limit on your route so you can drive safely and avoid costly speeding tickets. The feature is enabled by default on Android phones, and you can enable it on iOS by following these instructions.
The maps show speed limits for each roadway, including highways. Major roadways such as interstates and freeways are highlighted in bolder colors while less significant roads, such as one lane streets in residential areas, appear fainter. Some maps also display work zones and variable speed limits.
Variable speed limits, which are indicated by changeable message signs, may differ from statutory speed limits. These are usually set by local traffic agencies as a result of an engineering speed study and are intended to provide guidance for drivers to reduce speeds in certain conditions, such as bad weather or congestion.
A number of popular navigation apps offer speed limit information to help drivers choose the safest and fastest routes possible. Navteq, which powers many in-car navigation tools, offers a detailed map of speed limits by road function class. The maps allow you to quickly compare the maximum speed allowed in different states, from Washington DC’s low limit of 55mph to Texas’s high of 85mph.
Crossings
A highway is a major obstacle for wildlife, which is often killed or injured in collisions with cars. To mitigate the impact of roadways on animals, crossing structures are becoming increasingly popular. These structures, which include bridges and overpasses, tunnels, viaducts and culverts, can connect animal habitats across roads. They also reduce the ecological impacts of highways by reducing animal mortality and reconnecting wildlife corridors. A recent study found that wildlife crossings in Banff National Park, Canada, helped grizzly bears (Ursus americanus) maintain a large enough pool of mates and reduced the number of car-wildlife collisions by 80 percent.
Crossings may be marked with modules for traffic lanes, pedestrian crossings or other features, such as islands or raised surfaces. In general, the module for a pedestrian crossing is a dash in the middle, while the one for vehicle lanes is a solid line. Other types of crossings are represented by other symbols. For example, a call button is shown as an arrow with a square at the end and a HAWK beacon is represented by two points next to each other.
Some crossings are designed specifically for pedestrians, and are sometimes called zebra crossings. These are characterized by alternate black and white stripes, and usually prioritize pedestrians over road traffic. They can also be augmented with other pedestrian-oriented design features, such as call buttons, pedestrian signals or traffic lights.
Symbols
A highway map will include symbols representing the different types of roadways on the map. The symbols can also be used to indicate speed limits, pedestrian crossings, and other aspects of the highway network. A typical road map will also contain a compass rose to show which direction the road is going. The symbol is typically a red circle with a white cross inside it, although the color and style of the compass rose can vary from map to map.
Usually, major roadways will appear bolder on the map than lesser roads, such as one-lane streets in residential areas. This is to help motorists distinguish between roads and find them more easily. Other road map symbols may include the type of roadway, such as an interstate highway or a county highway. Some maps will also use color to identify different types of road.
Some states, such as Oklahoma, will include a state outline on the shield of their primary state-numbered highways. However, other states are free to choose their own design for these routes. For example, New York City has a unique symbol for its secondary state-numbered routes.
A highway map may also show road or trail designations that are only valid during certain times of the year. For example, a forest route will be marked with a special symbol that indicates limited cross-country motor vehicle access for the purpose of dispersed camping and game retrieval.