You can also use the URL rewrite module to enforce your SEO requirements throughout the site, without the need to write specific route functionality. This is managed from your web.config...
<rewrite>
<rules>
<rule name="Remove trailing slash" enabled="true" stopProcessing="true">
<match url="(.*[^/])/$" />
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
<add input="{REQUEST_METHOD}" pattern="POST" negate="true" ignoreCase="true" />
</conditions>
<action type="Redirect" redirectType="Permanent" url="{R:1}" />
</rule>
</rules>
</rewrite>