My interpretation is that in a state has an &quot;absolute&quot; speed limit law then you have a successful defense against a ticket for going at the speed limit in the left-most lane when there is faster traffic.<p>If you are in a state which does not have an absolute speed limit law, then you do not have that defense, and can be fined for going at the speed limit in that situation.<p>Here is a breakdown of the state laws (undated, and no promises that it&#x27;s correct or still true) - <a href="http:&#x2F;&#x2F;www.mit.edu&#x2F;~jfc&#x2F;right.html" rel="nofollow">http:&#x2F;&#x2F;www.mit.edu&#x2F;~jfc&#x2F;right.html</a> . The bottom has the following:<p>&gt; The Uniform Vehicle Code states:<p>&gt;    Upon all roadways any vehicle proceeding at less than the normal speed of traffic at the time and place and under the conditions then existing shall be driven in the right-hand lane then available for traffic ...<p>&gt; This law refers to the &quot;normal&quot; speed of traffic, not the &quot;legal&quot; speed of traffic. The 60 MPH driver in a 55 MPH zone where everybody else is going 65 MPH must move right. Contrast Alaska&#x27;s rule, 13 AAC 002.50, allowing vehicles driving at the speed limit to use the left lane, and Colorado rev. stat. 42-4-1103, prohibiting blocking the &quot;normal and reasonable&quot; movement of traffic.<p>&gt; Enforcement is inconsistent. Toledo police used to ticket truck drivers for driving at the 60 MPH speed limit in the left lane. Police looking for criminal activity frequently use the &quot;keep right&quot; law as a pretext to stop a suspicious car. On the other hand, a New York judge announced that he would not convict drivers for blocking speeding traffic, People v. Ilieveski, 175 Misc. 2d 943; 670 N.Y.S.2d 1004 (Monroe County N.Y. 1998).