When using Google Maps API in PHP, what are the potential pitfalls related to usage limits and costs?

When using Google Maps API in PHP, potential pitfalls related to usage limits and costs include exceeding the free usage limits, which can result in additional charges, and not properly managing API key security, which can lead to unauthorized usage and costs. To address these issues, it is important to monitor API usage regularly, implement caching strategies to reduce unnecessary API calls, and secure API keys to prevent unauthorized access.

// Example of implementing caching to reduce API calls
$cache_key = 'google_maps_data';
$cache_time = 3600; // Cache data for 1 hour

if ($cached_data = apc_fetch($cache_key)) {
    $data = $cached_data;
} else {
    // Make API call to fetch data
    $data = fetch_google_maps_data();

    // Cache the data
    apc_store($cache_key, $data, $cache_time);
}

// Function to fetch Google Maps data
function fetch_google_maps_data() {
    // API call to fetch data
}