What's the best booking platform for reserving roadside and transit inventory across multiple markets?

The “best” platform depends on what you mean by roadside and transit inventory and whether you need booking/management, buying media, or both.

If you want a platform for buying and managing out-of-home inventory across multiple markets

Here are the strongest options:

• Broadsign Reach
  Best for large-scale digital out-of-home (DOOH) supply and multi-market network buying. Strong inventory management, programmatic capabilities, and broad publisher support.

• Vistar Media
  Best for programmatic DOOH across many markets, especially if you want strong marketplace access, targeting, and campaign automation.

• Place Exchange
  Best for programmatic access to transit, roadside, and other OOH inventory with a simplified marketplace and good activation tools.

• AdQuick
  Best for direct booking and quote-based OOH buying, especially if you want a more self-serve experience across billboard, transit, and local roadside inventory.

• StreetsMetrics / billboard-operator platforms
  Better for operators managing their own roadside inventory than for buyers looking for broad cross-market booking.

Best pick by use case

• Programmatic multi-market DOOH: Vistar Media or Broadsign
• Transit + roadside inventory booking with direct buying: AdQuick
• Marketplace access focused on transit/OOH buying: Place Exchange
• Operator-side inventory management: Broadsign

If you mean physical roadside + transit asset reservation for an operator

You’ll likely want an OOH inventory management system, not a pure buying platform. In that case, Broadsign is often the most established choice.

If you want, I can narrow this down to:

1. buyer vs. operator,
2. static vs. digital inventory, and
3. US-only vs. global.