$fn=64;

// --- Parameters ---
tile_size = 50;         // Length and width of the road tile
base_thickness = 5;     // Total thickness of the tile at the highest point (sidewalk)
road_depth = 1.5;       // Depth of the road relative to the sidewalk
road_width = 30;        // Width of the road surface
line_width = 2;         // Width of the center dividing lines
line_length = 8;        // Length of each center line segment
line_spacing = 8;       // Space between center lines
line_height = 0.6;      // Height of the center lines (raised for 3D printing)

module straight_road() {
    road_thickness = base_thickness - road_depth;
    
    union() {
        difference() {
            // Main solid tile block
            translate([-tile_size/2, -tile_size/2, 0])
                cube([tile_size, tile_size, base_thickness]);
            
            // Subtract the road surface (extended in Y and Z to ensure manifold geometry)
            translate([-road_width/2, -tile_size/2 - 1, road_thickness])
                cube([road_width, tile_size + 2, road_depth + 1]);
        }
        
        // Add raised center lines
        num_lines = floor(tile_size / (line_length + line_spacing));
        total_lines_length = (num_lines * line_length) + ((num_lines - 1) * line_spacing);
        start_y = -tile_size/2 + (tile_size - total_lines_length) / 2;
        
        for (i = [0 : num_lines - 1]) {
            // Overlap slightly in Z (-0.01) to ensure manifold union
            translate([-line_width/2, start_y + i * (line_length + line_spacing), road_thickness - 0.01])
                cube([line_width, line_length, line_height + 0.01]);
        }
    }
}

// Render the model
straight_road();