What are highways?
A highway is a road that’s in the public domain and open to public use and which has one or more lanes for each direction of traffic. It differs from a general road in that it has a limited number of accesses from adjoining properties, and it doesn’t intersect any other type of road on the same level.
What is the fundamental difference between a highway and a freeway?
In Spain and other countries, there is a clear difference between a highway and a freeway. However, the following characteristics are generally agreed upon:
- There are separate lanes for each direction of traffic.
- Adjoining properties have limited access.
- They do not cross or are intersected by other roads or by railway or tram lines, or by any easements.
- The minimum speed is 60 km/h (any vehicle not reaching this required minimum must turn on its emergency lights and turn off the road at the nearest exit).
- The maximum speed is 120 km/h.
Although both share a restricted use of certain types of traffic, the fundamental difference is that the former (highways) allows other modes of transportation to travel on them (not only automobiles) because they are generally old radial roads that have been widened, and there are no alternate routes. Therefore, in these exceptional cases when there are no alternate paved roads or service roads, other types of vehicles may use the highway, including bikes, agricultural machinery, pack animals, etc.
An example: the Valladolid-Tordesillas section of the A-62, the Autovía de Castilla, was built by making use of the path of the N-620. Since there is no paved alternative along its entire length, this highway does not prohibit other types of vehicles from using it.
Another important difference is that no Spanish highway has a toll. However, the fact that freeways don’t have tolls doesn’t mean they are highways. The criterion for classification is still vehicular access or restriction based on the availability of alternative routes.
The third difference between highways and freeways is the number of entry and exit ramps. Highways are accessed by lanes for acceleration and deceleration, and there’s no limitation on the number of junctions; freeways, on the other hand, do tend to limit the number of entrances and exits.
The last key difference between freeways and highways lies in their layout; the former is specially designed to allow traffic to maintain a constant maximum speed. Freeways are designed with wide radius curves and have longer acceleration and deceleration lanes (something that’s common but not mandatory when designing highways).
In Argentina, the term “autovía” or highway is used to designate any road with separate lanes that has intersections at the same level. Argentina’s freeways, on the other hand, don’t have intersections at the same level. Two examples are Highway 2 and the Rosario-Córdoba Freeway.
What are other features of highways?
- Rest areas and road services.
- In the event of a road closure or traffic, the medium-sized highways have special openings that let cars travel in the opposite direction.
- There’s no limit on the number of entrances and exits.
- When two highways cross perpendicularly, a cloverleaf connection is made.
- If the highway intersects with other roads, it may use turn-offs or have road junctions.
What will the highways of the future look like?
When designing new roadway infrastructure projects or improving existing routes, there is much to consider. Not only is there the decision between building a freeway or a highway: the ecological footprint of the new infrastructure must be considered, as well as how new smart technologies can be integrated to improve traffic and the user experience.
The new forms of road management, like Cintra’s AIVIA Orchestrated Connected Corridors project, will make the following possible:
- Orchestrated, dynamic traffic management.
- Greater connectivity and sensorization along the road.
- Increasing roadway safety.
- Reducing travel time.
- Lowering traffic on the road.
- Fully harnessing innovations like 5G, advanced monitoring and simulation technologies, and sensory technology
Modern highway and freeway layouts must also take the ecological impact of construction into consideration. Companies like Ferrovial have increasingly focused on designing compensatory environmental measures to ensure the recovery of biodiversity in the area around the new highway.
Fun facts about highways
- The Meseta A-67 highway is the most expensive one built in Spain, costing €16 million per kilometer. This is because of its five viaducts, including the tallest in the country: the Montabliz Viaduct.
- In Spain, it is estimated that the average cost of a kilometer of highway is €6.2 million, while the average cost of a kilometer of freeway is €11 million.