<?xml version='1.0' encoding='utf-8'?>
<section article="gtr" article_name="Transportation" number="21-1412" title_number="21" title_name="Vehicle Laws -- Rules of the Road" subtitle_number="14" subtitle_name="Operation of Vehicles on Certain Toll Facilities">
  <level label="a">
    <text>Except at the direction of authorized personnel, vehicular traffic may not cross the double white lines that designate the vehicular traffic lanes in a tunnel.</text>
  </level>
  <level label="b">
    <text>Except at the direction of authorized personnel, trucks and slow moving vehicles may be driven only in the right lane of a tunnel.</text>
  </level>
  <level label="c">
    <text>The driver of a vehicle may not sound his horn or flash his headlights in a tunnel.</text>
  </level>
  <level label="d">
    <text>While in a tunnel, a person may not use any cutout or other device that allows exhaust gases to escape a motor without passing through a muffler or silencer.</text>
  </level>
</section>
