# What are the new I-15 underpasses in St. George? > Two crossings under the freeway at 400 East and 900 South, folded into the Exit 6 to Exit 8 widening. Why residents asked for them and who they help. - Author: Kelsey Earl, Realtor, Keller Williams South Valley - Location: St. George, Utah - Section: The Washington County Insider - Published: 2026-10-30 - Canonical: https://homesbykelseyut.com/blog/what-are-the-new-i-15-underpasses-in-st-george - Contact: 801-419-8917 ยท Kelsey.earl@kw.com --- **Quick answer:** Two new St. George crossings beneath I-15 connecting 400 East and 900 South, funded by a federal grant and built as part of the Exit 6 to Exit 8 widening. They exist because residents asked for east-west connections across the freeway, which has divided those neighborhoods since it was built. --- The new underpasses are two crossings beneath Interstate 15, connecting 400 East and 900 South ([St. George News, March 14, 2024](https://www.stgeorgeutah.com/news/government-news/we-are-so-thrilled-udot-receives-86-million-grant-to-fund-new-i-15-underpasses/article_4485bd0e-d9d9-58d4-80b8-44fcda093257.html)). They are being built as part of UDOT's widening of I-15 between Exit 6 and Exit 8 ([UDOT, March 26, 2026](https://connect.udot.utah.gov/2026/03/26/udot-announces-2-8-billion-in-new-and-ongoing-2026-construction/)). They get far less attention than the freeway widening they are attached to, and for the neighborhoods either side of the interstate they are probably the more consequential piece of the project. ## Why they exist The short version is that residents asked for them and had to wait. During public input on a proposed I-15 interchange at 700 South in 2022, residents asked UDOT to look at underpasses. UDOT did not include them, on the basis that they would not address that interchange's traffic goals, and building them would require a separate project with funding that was not available. The city applied for a federal grant in 2022 and was unsuccessful. UDOT applied the following year and received funding through the federal Reconnecting Communities and Neighborhoods program ([St. George News, March 14, 2024](https://www.stgeorgeutah.com/news/government-news/we-are-so-thrilled-udot-receives-86-million-grant-to-fund-new-i-15-underpasses/article_4485bd0e-d9d9-58d4-80b8-44fcda093257.html)). The name of that program is the clue to the purpose. It funds projects that reconnect neighborhoods divided by infrastructure, and a freeway through a city is the classic example. Reported figures for the award differ within the coverage itself, so I am not going to quote one. The 700 South interchange that started this conversation was not built. The plan keeps the existing structures at 100 South and 700 South and adds the new crossings instead. ## What a crossing actually does for a neighborhood This is the part worth understanding, because it is easy to hear "underpass" and picture a minor convenience. A freeway running through a city cuts the street grid. Every connection it severs forces trips onto the few remaining crossings, which means longer journeys, more traffic concentrated at those points, and two sides of one neighborhood that function as separate places. Restoring a crossing reverses a piece of that: - Local trips get shorter, because you are no longer routing to the nearest interchange to go half a mile - Walking and cycling become possible between places that were technically close and practically unreachable - Traffic spreads across more crossings instead of piling onto the existing ones - Children can reach schools, parks and friends without an adult driving them to the other side That last one is the effect residents usually raise first and planners usually count last, and it is the one most likely to matter to a family choosing between two houses. ## What it means for property nearby Honestly: a modest positive, over a long horizon, and not something to trade on. Improved connectivity tends to support values because it makes a location more usable. A house that is suddenly a short walk from amenities on the other side of the freeway is a better house than it was, and nothing about it changed. But this is not an announcement that moves prices. It is infrastructure that will take years to finish and whose effects arrive gradually. I have watched buyers try to time purchases around public works and the pattern is reliably disappointing, by the time something is announced, whatever it was going to do is largely in the price, and the construction years arrive before the benefit does. The same reasoning applies to the larger projects running alongside it, which I have set out in [how long the road construction will last](/blog/how-long-will-the-road-construction-in-st-george-last/) and, for the surface corridor, in [what the Bluff Street construction is](/blog/what-is-the-bluff-street-construction-in-st-george/). ## How this fits with the widening it rides along with The underpasses are not a standalone project. They are folded into UDOT's widening of I-15 between Bluff Street at Exit 6 and St. George Boulevard at Exit 8, which adds a third lane in each direction and is listed at $175 million, running from summer 2026 to winter 2028 ([UDOT, March 26, 2026](https://connect.udot.utah.gov/2026/03/26/udot-announces-2-8-billion-in-new-and-ongoing-2026-construction/)). Bundling them makes sense and it has a consequence worth knowing. Building a crossing under a live interstate means working on the structure itself, so the crossings arrive on the widening's schedule rather than on their own. You do not get the underpasses early because the neighborhood wants them early. It also means the neighborhoods that stand to benefit spend the construction period absorbing the disruption of a freeway widening in exchange for a connection that arrives at the end. That is a reasonable trade and it is still a trade, and if you are buying there now you are buying the first half of it. The practical reading for a buyer: assume the inconvenience is real and current, and assume the benefit is real and some years out. Both are true, and whichever one you hear about depends entirely on who is telling you. ## Who should actually care **Buyers looking at the neighborhoods either side of the freeway between the Boulevard and the south end of town.** If you are weighing a house on one side and the things you use are on the other, this changes your daily life in a few years. That is a legitimate factor. **Families.** The walkability effect is real and it is the kind of thing people notice every week rather than once. **Anyone who assumed those neighborhoods were cut off permanently.** They were, and they are being reconnected. That is a reasonable reason to look again at an area you had written off. **Not** anyone hoping to buy ahead of an announcement. You are reading the announcement. I am Kelsey Earl, a Realtor with Keller Williams South Valley. What I actually see is that buyers moving here from larger cities read a map and assume two points close together are easy to travel between. In a city divided by a freeway that is often wrong, and it is worth driving the route before you assume it. ## How to check it yourself UDOT's project page for the Exit 6 to Exit 8 widening is the authority on scope and schedule, and it will reflect changes that news coverage from two years ago does not. For a specific house, do the simple thing: drive from the address to the three places you actually go most. That tells you whether a new crossing would help you or whether your trips run a different direction entirely. And check dates on anything you read about this project. The underpasses were first reported in 2024, the plan has changed since, and a fair amount of what circulates describes a version that is no longer current. If you are looking at either side of the freeway and want to think through what the finished road network does to a particular address, [send it to me](/contact). --- Source: https://homesbykelseyut.com/blog/what-are-the-new-i-15-underpasses-in-st-george Any market figure in this post is accurate only where a date and source are stated alongside it.