Matthew J. Flannery
President and Chief Executive Officer at United Rentals
Thank you, operator. And good morning, everyone. Thanks for joining our call. As you've heard us say since the beginning of the year, 2023 is about raising the bar off of last year's record results our second quarter performance across growth, profitability and returns provides evidence of that. I'm pleased with how the year is playing out, including the Ahern integration, which remains on track. Of course, key to all of this is our employees who do an exceptional job supporting our customers every day.
Without them, we wouldn't be able to generate the results we consistently deliver. And I'm pleased to report that once again, they've done this with safety at the forefront as our company-wide recordable rate remained well below one in the second quarter. Importantly, our growth shows that we continue to outpace our underlying markets as we leverage our competitive advantages to provide a superior level of customer service.
So let's dig into the results. Total revenue rose by 28% year-on-year to a second quarter record of almost $3.6 billion. Within this, rental revenue grew 21% as reported with broad-based demand across verticals regions and customer segments, while fleet productivity increased 2.1% on a pro forma basis. Adjusted EBITDA increased 29% to a second quarter record $1.7 billion driving solid margin expansion. Adjusted EPS grew by 26% to a second quarter record of $9.88. And critically, our return on invested capital set another new high watermark at 13.4%.
In short, we're on track for another record year driven by robust customer activity. And the increases to our full year guidance reflects our continued confidence in customer demand. Used equipment sales were another highlight in the quarter. We generated a record second quarter proceeds of $382 million. The retail market remains very strong and we also broadened our channel mix as we discussed we would last quarter.
Combined with the improvements we've seen across most of the supply chain, this has allowed us to refresh our fleet by rotating some of the older assets out. As you saw, rental capex totaled $1.25 billion in the quarter, in line with our expectations and helping to ensure that we have the capacity our customers need to support their projects today and going forward. And as I alluded to earlier, the integration of Ahern remains on track. The teams have come together especially well, and our second quarter results reflect the ongoing improvements in the efficiency of their business.
And at this point, we're focused on optimizing the combined branch network and fleet, which should be completed by year-end. Now let's take a closer look at the second quarter demand. Key verticals saw broad-based growth led by industrial manufacturing, Metals & Minerals and Power. Nonres construction was also up double digits. Within this, our customers kicked off new projects across the board, including numerous EV plants and semiconductor plants, solar power facilities, infrastructure projects and for the Buffalo Bill fans out there, a new stadium.
Geographically, we saw growth in all of our regions on both the reported and pro forma basis. And our specialty business delivered another excellent quarter with rental revenue up 17% year-on-year organically, and double-digit gains across all major categories. Within Specialty, we opened 19 new locations in the second quarter and are on track for the 40 cold starts this year. Turning to capital allocation. We returned over $350 million to shareholders during the quarter through share buybacks and dividends are on track to return over $1.4 billion of cash to shareholders this year.
And our balance sheet remains in excellent shape. Looking ahead to 2020, 2023 is on track to be another record year across a variety of KPIs, including revenue, EBITDA, EPS and returns. We're encouraged by the customer sentiment and external indicators, which point to growth and give us confidence in our updated guidance. For example, the ABC's contractor confidence index remained strong across the second quarter as did its backlog index.
The Dodge Momentum Index was up 19% year-over-year in June, while nonres construction employment growth also remains solid. And most importantly, our own customer confidence index continues to reflect their optimism. Beyond 2023, we remain positive on the longer-term outlook. Driven by key tailwinds, including infrastructure, industrial manufacturing and energy and power. As we shared at our Investor Day in May, we spent the last decade building unique and diverse capabilities that position us very well for the $2 trillion plus of construction projects underpinned by these tailwinds over the next decade.
Put simply, our advantages across scale, complex solutions, technology and people put us in a first call position. And we believe this provides a platform for leveraging our resilient business model and pursuing continued growth, both organically and through M&A. Finally, I want to highlight our new sustainability report, which we released yesterday. While there's a lot of great content in that report that we're very proud of.
This year, I'd especially point out to the work our team has done quantifying how the rental business model aligns with key aspects of sustainability. For example, less equipment needs to be manufactured because of rental, which has clear benefits. While the equipment that we have in our fleet also helps our customers reduce their emissions intensity based on its younger age and greater fuel efficiency.
And not only does this benefit our customers, we believe that it also benefits our employees, the communities we're operating in and our shareholders. Before I hand the call over to Ted, I'll sum up today by saying I'm very pleased with how the year is playing out. We entered 2023 with high expectations. And as you can see through our results, that's what we're delivering. We feel good about the rest of the year and what's ahead for United Rentals and our investors.
And with that, I'll hand the call over to Ted before we open the line for Q&A. Ted, over to you.