Driving on Highways
Understanding Highways

Understanding Highways: Driving Risks, Road Rules, Signs & Restrictions

Updated Aug. 14, 2020

Highways are usually the best roads to use when traveling long distance. These roads are also known as expressways, limited access highways, interstate highways, turnpikes, toll roads and freeways. Most highways have two to four lanes of traffic moving in each direction, with opposing traffic separated by a central barrier or median.

Highways facilitate faster travel and have higher speed limits than other roads, as they do not have intersections that would require drivers to yield or stop. Only at set interchanges can motorists enter or exit a highway. Often, these access points will be many miles apart.

Highway driving advantages

Highways allow motorists to travel long distances quickly and conveniently, thanks to their higher speed limits and the relatively straight paths they cut across the country. Aside from this, highway driving has a few other advantages:

  • Multiple lanes allow large volumes of traffic to move without congestion.
  • Motorists using a highway do not have to worry about cross traffic.
  • Safety is maximized by the central barrier which separates opposing streams of traffic.
  • Pedestrians, cyclists, animal-drawn vehicles and many light-weight two-wheel motor vehicles are not allowed on highways.
  • Clear signage and traffic control tactics make it easy for drivers to navigate and obey highway rules.

These advantages add up to driving conditions that are among the safest you will experience. However, there are still risks to highway driving. While accidents are rarer on highways than other roads, they are often catastrophic when they occur. When driving at highway speeds, drivers must remain alert and be able to make split-second decisions to avoid collisions.

Highway driving risks

Freeways are only our country’s safest roads when you know how to drive on them correctly. Safe highway driving begins with understanding the risks involved. When traveling at high speed, amidst large volumes of traffic, enormous trucks and ever-changing conditions, motorists must be at the top of their driving game. Keep the following risks in mind when driving on an interstate highway:

  • Traveling at high speed means your total stopping distance will be longer than on other roads.
  • Wet highway surfaces can lead vehicles to hydroplane.
  • When highways pass through cities, entry and exit ramps will increase in number.
  • Other motorists may drive in a cluster.
  • Highway drivers are more easily distracted than other road users, due to the monotony of the driving environment.
  • Driving too fast may leave you without a safe following distance.
  • Your view of the road may be impeded by large vehicles.
  • Two vehicles may attempt to merge into the same lane simultaneously.
  • Traveling long distances can result in driver fatigue and the threat of falling asleep at the wheel.
  • “Highway hypnosis” can occur. In this altered psychological state, drivers can travel long distances and execute maneuvers without any recollection of having done so.

Choosing the correct lane, moderating your speed, maintaining a sufficient following distance and taking regular breaks are the best ways to manage the risks associated with highway driving.

Speed limit on highways

Across the United States, highway speed limits usually fall between 55 and 75 mph, though there are exceptions. It is imperative that you check your driving handbook for highway speed limit rules in your state.

Driving too slowly on a highway can be every bit as dangerous as driving too fast. Keep in mind that many states impose a minimum speed limit of 50 mph when the maximum signposted speed limit is 70 mph. Each state also sets a maximum highway speed which drivers must adhere to if no other signs are posted stating otherwise. In Florida, the max speed allowable on limited-access highways is 70 mph.

When highways pass through urban areas, the increase in entry and exit points will likely be reflected in a lower speed limit. Signs indicating the change in limit will be posted at regular intervals.

The “basic speed" rule

Drivers must remember that when moderating speed, they may not drive up to and including the maximum speed limit if traffic conditions do not safely allow it. This is known as the “Basic Speed Rule”. If you are caught driving too fast for traffic and road conditions you will be prosecuted, regardless of the “legal” speed limit.

Highway restrictions

The main highway restrictions you must adhere to are listed below.

  • Never drive over the barrier or median which separates opposing traffic.
  • Never make a U-turn on a highway.
  • Only enter a highway using an approved entry-ramp.
  • Never stop or park on a highway, unless using the shoulder in an emergency.
  • Do not reverse along a highway if you miss your exit. No matter how inconvenient, you must continue to the next exit.
  • Never use HOV lanes without observing HOV rules.
  • Do not follow other vehicles too closely. Rear-end collisions are common on highways.
  • Always observe safe passing and lane-changing best practices.

Keep in mind that these restrictions generally reflect extremely dangerous driving behaviors. As a result, serious penalties can be incurred by breaking the rules. For instance, improper passing on a highway comes with a penalty of four license points in many states.

The "Move over" law

In states where the “move over” law or similar rules apply, highway drivers must move over a lane or slow down when approaching a stopped emergency response vehicle or tow truck, displaying flashing or amber warning lights. Tow truck drivers, police officers, paramedics and other emergency response personnel are subject to great risk of injury when assisting the public on a highway. The move over law was introduced in California, New Jersey, Florida and many states to protect these workers. Check your state’s own driving manual for details.

Fines for violating the move over law vary from state to state. In New Jersey, drivers found failing to move over will be subject to a fine of at least $100, which could be as high as $500, depending on the severity of the offense.

Highway road signs and markings

Observing signs, signals and pavement markings is imperative for safe highway driving. Fortunately, highway signs are typically easy to understand and regularly posted. They also provide additional information to help drivers navigate and find their location on a map. Here are the most common signs you will encounter on an interstate highway:

  1. 1

    Speed limit signs:

    You will encounter maximum and minimum speed limit signs on interstate highways. Be aware that separate speed limit signs will be present on exit ramps, indicating how fast you should travel when leaving the highway.

  2. 2

    Guide signs:

    These are usually green with white letters. Guide signs indicate which routes take you to which destinations and what distance is left until the exit. Usually, two guide signs are posted within a mile in advance of the exit and a third is posted at the exit itself.

  3. 3

    Mile markers:

    These green signs help motorists to keep track of the distance they have traveled and prepare to exit when their destination approaches.

  4. 4

    Interstate number signs:

    Distinctive shield-shaped signs. Single or double-digit, even-numbered highways follow an east-west route. While single or double-digit, odd-numbered highways follow a north-south route.

    Triple-digit highways usually indicate connecting roads. If the number is even, the road is circular and moves around a city. If it is odd, it travels through the center of a city.

  5. 5

    “DO NOT ENTER” and “WRONG WAY” signs:

    You may see these red warning signs if you drive onto a highway exit or entry ramp in the wrong direction. You MUST turn around when encountering one of these signs on a freeway ramp, but keep in mind that this is the ONLY circumstance in which reversing your course on a highway is permitted.

With basic highway information out of the way, the next sections of the program will discuss safe highway driving tactics, safety features and navigating interchanges – everything you need to master interstate travel!

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