2.2 Warning Signs & Guide, Route, Service and Mile Marker Signs

What Warning Signs Do

The manual describes warning signs simply: they "provide notice to road users of a situation that might not be readily apparent." Most are yellow diamonds with black symbols; school-related ones are fluorescent yellow-green, and work-zone ones are orange. A warning sign is not a command in itself, but it tells you a hazard is coming. You may have to slow down, change lanes or stop.

Warning Signs in the Maryland Manual, by Group

Traffic Control Ahead

• Stop Ahead, Yield Ahead and Signal Ahead warn that a stop sign, yield sign or traffic light is hidden by a curve, hill or trees. Begin slowing early.

Road Alignment

• Sharp Right Turn, Road Curves and Sharp Turns show the shape of the road. Slow down before the curve, not in it.
• Steep Hill warns of a grade where you may need a lower gear and more braking distance.

Intersections and Merges

• Intersection, Side Road Enters Ahead and "T" Intersection Ahead warn of cross traffic and of roads that end.
• Railroad before "T" Intersection warns of tracks just before a T-junction, so you may need to stop for a train and then for cross traffic.
• Traffic Circle/Roundabout warns of a circular intersection; you will yield to traffic already in the circle.
• Two Roads Merging, Lane Ends and Lane Ends Merge Left warn that lanes are combining. Adjust your speed and merge smoothly.
• Road Divides Ahead and Divided Road Ends Ahead warn that a median begins or ends. When a divided road ends, two-way traffic returns.

Speed and Passing

• Speed Limit (ahead) warns of a lower limit coming up.
• Exit Ramp Advisory Speed shows the recommended safe speed on a ramp.
• No Passing Zone (pennant) marks where passing stops being allowed.

Surface and Visibility

• Slippery When Wet warns that the surface loses traction when wet. Slow down and avoid sudden braking or steering.

Crossings

• Pedestrian Crossing, Trail Crossing, Pedestrian and Bicycle Crossing, Deer or Other Wildlife Crossing and Truck Crossing warn of places where people, animals or large trucks may enter the road.

Schools and Buses

• School Crossing Ahead and School Bus Stop Ahead warn of children and stopped buses (see Section 6.4).

Work Zones (Orange)

• Flagger Ahead, Roadwork Ahead, Detour, Begin Work Zone and End Active Work Zone.
• Work Zone Active When Flashing (increased fines): when the lights flash, workers are present and higher fines apply (see Section 4.5).

Advisory Speeds

A small yellow plaque with a speed, for example under a curve sign or on an exit ramp, is an advisory speed. It is the safe speed for that feature in good conditions. It is not the posted limit, but driving faster greatly increases the risk of running off the road, and in rain or snow you should go slower still. Maryland's basic speed rule requires a speed that is reasonable for the conditions.

Other Traffic Sign Types

Overhead Lane-Use Signs

Large signs above the road show destinations, directions and which lanes go where. Read them early so you can change lanes before the split.

Route Marker Signs

Numbered roads have route markers that identify the route number and the type of road: Interstate, U.S. Route and State Route markers each have their own design. On interstates, odd numbers generally run north-south and even numbers east-west.

Service Information and Guide Signs

These identify businesses and services at upcoming exits: Park and Ride, destination guide signs, general services signs, and symbol signs for lodging, hospital, gas, food, airport and train station. Blue signs show services, green signs show destinations and distances, and brown signs show recreation.

Mile Marker Signs

Mile markers are placed every mile on interstate highways. They give location information you can use if someone needs to find you, such as a tow truck or emergency personnel. Make a habit of noting the last marker you passed; it makes a 911 call much faster.

Putting It Together

Scenario 1: You crest a hill and see a yellow diamond with a traffic-light symbol. A signal is ahead and may already be red, so ease off the gas and cover the brake.

Scenario 2: On I-95 your car loses power. Pull onto the shoulder, turn on your flashers, and tell the 911 dispatcher your direction of travel and the nearest mile marker.

Scenario 3: An orange sign reads Flagger Ahead. Expect a person with a STOP/SLOW paddle, and obey the flagger's directions.

Exam Tips

• Yellow diamond = warning; orange = work zone; fluorescent yellow-green = school, pedestrians or bicycles.
• "Mile markers" questions usually test their purpose: helping responders find you.
• Questions about route markers expect you to know they identify the route number and type of road.