Great question! In the case of the ICE Virtual Library, that publisher owns the rights to the articles it publishes so it is no surprise that most come with a subscription fee.
From an accessibility standpoint anyone (including non-subscribers) can access an Open Access article in ICE or an article that ICE decides to make "Free" from their site.
In the latter case, the publisher chooses to make selected articles available to the research community free of charge, like the lead article (which is an Editorial) in this issue of Bridge Engineering. For that matter, the publisher can even make a complete journal issue free to the research community to help promote a new journal, like ICE did with Volumes 1 and 2 of "Smart Infrastructure and Construction."
Open access (OA) is a little different, but many user equate Open Access with "free" because neither type of resource sits behind a paywall.
Open Access is actually a type of freely available, electronic journal article that typically also carries less restrictive copyright and licensing barriers than traditionally published scholarly journal articles. There are many kinds of Open Access, and OA articles can typically be accessed by the research community without charge.
That's usually because their publication was paid for through other means, including in some cases partial funding funded by other article subscriptions. Since open access publication does not charge readers, there are many financial models used to cover costs by other means. In one model of Open Access, journals generate revenue by charging publication fees in order to make the work openly available at the time of publication.
In other cases, OA is achieved through publisher imposed "Article Processing Charges" (APC), whereby authors (or institutions or research funders, on behalf of authors) pay a fee to cover supposed publishing costs. In this model the money might come from the author but more often comes from the author's research grant or employer. Either way, technically, somebody is paying for the article to be published and also paying for it to be made freely accessible to others.
In Vol. 127, No. 4 of the journal Transport, we see that the first article is made "free" by ICE (it is an Editorial). The following four articles are only accessible to subscribing customers. The article after that is labeled "Open Access" and if you look closely you may see this wording with it:
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The final article in Vol. 127, No. 4 is also made "free by ICE.
That represents a potentially confusing mixture of paid content, content the publisher decides to make "free," and content that has been paid for in order to make it "Open Access."
There is a growing trend for Open Access scholarly journal publishing, and there are a growing number of journals that are 100% Open Access. Right now ICE publishes one OA Journal: Geotechnical Research, in which all articles are Open Access.
From an accessibility standpoint anyone (including non-subscribers) can access either an Open Access article or a "Free" article.
To learn more about Open Access we recommend reviewing our guide Understanding Open Access.
