Head north on the Monon past 156th Street this fall and the paved trail just stops. Orange barricades cut across the asphalt, a sign points toward the street, and regular walkers and cyclists who've made this stretch part of their routine for years are suddenly sharing pavement with cars for a few blocks. This isn't new information to anyone who uses the trail daily, but the reason behind it, and what's popped up at either end of the disruption, is worth laying out plainly.
Westfield is building the tunnel under 161st Street, where a runner was struck and injured in 2019. The city installed a signalized HAWK crosswalk in 2021 that let pedestrians push a button to activate stop signals for drivers on 161st Street. City council later debated funding a permanent underpass, and the project was shelved and later revived before construction began.
Monon Tunnel Construction and Schedule
According to the city's own public works schedule, work on the Monon Tunnel began in early March 2026 and is expected to wrap by the end of this year, at an estimated cost of $8 million. That estimate followed earlier estimates ranging from $5.25 million to $9.9 million, depending on which version of the design was on the table. 161st Street carries roughly 14,000 vehicles a day, making it one of the busier crossings the trail intersects anywhere in Hamilton County.
The detour itself is straightforward once you know it:
- Trail users are routed off the Monon at 156th Street
- The marked path follows Oak Ridge Road west of the construction zone
- Riders and walkers rejoin the trail at 169th Street
That's roughly a mile and a half of street riding instead of paved trail, through a residential stretch with normal traffic and normal stop signs. It's not dangerous, but it's a noticeably different experience than the wide, uninterrupted path Westfield users are used to, and it's going to stay that way through December.
What's Waiting Once You Clear the Detour
Here's the part that doesn't show up on the construction signage. While this stretch of the Monon has been rerouted, the corridor on either side of it has kept building, and two of the additions are recent enough that even people who ride this trail weekly might not have caught up.
The most visible one sits just past the northern end of the detour zone. Westfield Collective opened on four acres at 181st Street and Grand Park Boulevard, close enough to where the Monon feeds into the Midland Trace Trail and the Grand Park Sports Campus that it functions as a natural stopping point for anyone continuing north. The food hall soft-opened in March 2026 and held its official grand opening on April 15. Inside are six independent restaurant concepts, none of which had a brick-and-mortar location anywhere else before this, alongside three bars and two self-pour walls for beer, wine, and cocktails. It was built with Grand Park's tournament crowds in mind, but for a trail user who's just spent a mile and a half detouring around a construction zone, it also works as a reasonable place to stop, eat something that didn't exist in Westfield a year ago, and decide whether to keep going.
Farther north, at 199th Street where the Monon runs its final stretch before crossing into Sheridan, the trail is getting a different kind of neighbor. Developers Onyx+East and IHP Capital Partners broke ground on July 13, 2026, on Trillium, a 44-acre community that will eventually include 119 homes. Ten of those homes are designed as courtyard units with direct access to the Monon itself, meaning the trail isn't a backdrop for this project so much as a stated part of its design. It's a small signal, but a clear one: even with a construction closure running through the middle of Westfield's trail segment this year, builders are still choosing to put new construction directly against it rather than near it.
Reading the Corridor as a Whole
Taken together, this is a version of a pattern that shows up in growing suburbs more often than people notice. The infrastructure that makes a corridor livable, in this case a paved trail connecting neighborhoods to parks and to each other, gets temporarily worse while the amenities around it get permanently better. The tunnel project is disruptive because it closes the trail while the city builds a tunnel at the one dangerous crossing on it. The same logic explains why a developer would anchor a new home community around trail access rather than around a cul-de-sac, and why a six-restaurant food hall would choose to sit exactly where the Monon meets Grand Park instead of somewhere with easier car access but no trail frontage at all.
None of this makes the detour less annoying in the short term. Riding street shoulders for a mile and a half is a worse experience than riding the trail, full stop, and it will stay that way until the tunnel opens. But the timing means that anyone who's been avoiding this stretch of the Monon because of the construction has also been missing the fact that the corridor around it kept moving. By the time the barricades come down in December, Westfield Collective will be a nine-month-old fixture rather than a new opening, and Trillium's first phase of homes will be further along than a groundbreaking photo. The disruption is temporary. What it's routing people past isn't.
If you're curious what else has changed on your own stretch of Westfield, or what a new development like Trillium actually means for the neighborhoods around it, Hundley Residential keeps a close eye on exactly this kind of local change and is always happy to talk through what we're seeing.
