Does the / at the end of a URL make a difference for SEO?

Building on Kevin's answer, the duplication caused by trailing slashes (or not) is a fairly significant problem which does have simple fixes, however the underlying reason for linking to the correct URL is interesting: Because search engines can not infinitely pass link equity between documents (otherwise every webpage would have an infinite link equity score), there is a proportion of degradation with every link or redirect. For instance, if a page has a link equity score of 100, and 1 outbound link, a search engine will degrade the equity by (say) 10% and pass a link equity score of 90 to the destination page (i.e. http://www.slideshare.net/kiwialec/technical-seo-presentation-from-london-affiliate-conference-2014/12). Google has said that with each redirect, there is the same amount of degradation as if a link was used. So if you have a page with a link equity score of 100 and link to one URL which redirects twice before getting to the real page, the destination page will only inherit a link equity score of 72.9 (100*.9^3). [these examples assume a degredation of 10% per link/redirect - this is nothing but a guess/easy number to do maths with. The actual number is probably different] By linking to /travel/ and letting it redirect to /travel, some link equity vanishes. There is some empirical evidence which shows that passing link equity to a destination page through the use of a canonical tag has the same amount of degradation as a redirect. TL;DR: It doesn't matter whether your site uses trailing slashes or not, as long as (a) Duplication is not caused by adding or removing the slash; and (b) You only ever link to the true URL.