It is consistent. It&#x27;s consistent with mph, which is what people have been using for decades to measure speeds.<p>Using a &#x2F; is technically correct, sure, but it&#x27;s also technical language and where I&#x27;m from people are unlikely to use that. They simply wouldn&#x27;t think to abbreviate the &#x27;per&#x27; in &#x27;kilometres per hour&#x27; to a slash, any more than they&#x27;d think to abbreviate &#x27;miles per hour&#x27; to &#x27;m&#x2F;s&#x27;. So, kph.