Does the Speed Limit Change Before or After the Sign in Colorado?

As I was driving to the Townsquare Media studios in Windsor the other day, it came time for me to switch from 45 mph to 55 mph.

Although I was still in a 45 mph zone, I could see the 55 mph speed limit sign ahead. I wondered: does the speed limit change when I can see the sign or after I pass it?

Let's investigate:

Colorado's State Speed Limits

According to the Colorado General Assembly, the state of Colorado adheres to general speed limits. These differ by area and can change depending on traffic and road conditions. However, if you're unsure of what the speed limit is, it's best to stick to the following:

• Blind curves & narrow mountain highways — 20 mph
• Business districts — 25 mph
• Residential Districts — 30 mph
• Open mountain highways — 40 mph
• Open highways that aren't interstates, four-lane freeways, or expressways — 55 mph
• Four-lane highways in the interstate system or expressways — 65 mph

When Colorado's Speed Limit Signs Take Effect

Still, if you can see a speed limit sign, can you start following it? Unfortunately, you may not like the answer.

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Karl Smallwood of Today I Found Out reports that the speed limit only changes once you've reached the sign. So, even though I can see the 55 mph sign ahead of me, I still have to go 45 mph.

>RELATED: New Study Says Colorado is One of the Worst States to Drive

"Contrary to what people may try to tell you, by the letter of the law there is no 'buffer' or grace period near a speed limit sign..." said Smallwood. "Any signposted speed limit comes into effect at the exact point the side resides."
Colorado does have a speed limit tolerance of five mph on highways, and traffic officers could decide to let you slide around speed limit signs. But, if you want to be safe, don't hit the gas until after that sign.