The right one (Slow Lane)... The left is for Passing
Middle lane at +/- 5 mph of posted speed limit
in the center lane
It separates two lanes traveling in the same direction
To indicate that traffic in that lane is flowing in the same direction as you are traveling.
On a road, a solid line divides lanes of traffic which are going in opposite directions. A line composed of dashes divides lanes of traffic going in the same direction.
same direction, if the lines are broken this means you are allowed to change lanes. If the line or lines are solid, you are not supposed to change lanes.
A white dotted/dashed line separates two lanes of traffic moving in the same direction. You are also legally allowed to pass other cars safely when you are in a section of road with dashed white lines.
On a two laned road, you have the double solid yellow lines to divide traffic. If it becomes a single dashed yellow line, you can pass. If it becomes a solid yellow line one one side and a dashed yellow line next to it, you can pass if you are on the dashed side. Otherwise, don't pass.
White lines are used to separate lanes of traffic going in the same direction.Solid White LineA solid white line indicates that moving between lanes is forbidden. You cannot cross a solid white line.Broken White LineThe broken white line indicates that moving between lanes is permitted. You may move between lanes as desired.For example a solid white line may be used to separate a dedicated bus lane from regular traffic. Where normal lanes are separated by the dashed line.
If you're asking in reference to America, the broken white lines are typically seen on any multiple lane road, highway, and freeway. These lines separate traffic lanes, going in a single direction on either side. It's okay to cross between lanes so long as the line is not solid, as many times as you like using proper signaling. Happy safe driving...
Lanes are usually about 11-12 feet wide, so a road with two lanes (one lane going in each direction) would be between 22 and 24 feet wide. A road with two lanes in each direction would be between 44 and 48 feet wide.
Anytime you see a yellow line on the road it means that the two lanes are for driving in opposite directions; a white line always means the two lanes being divided are for traffic moving in the same direction; broken lines on the road, regardless of the color mean it is ok and legal to pass another vehicle by moving into the other lane, passing the vehicle, and then returning to your original lane.