# Roadway Alignment

This section defines the horizontal, vertical, and transverse alignment for the Steel Tub Girder Bridge.

{% hint style="info" %}
**Navigation:** Bridge Geometry > Roadway Alignment

For detailed parameter explanations, see the [Roadway Alignment Reference](https://docs.openbrim.org/templates/steel-tub-girder-bridge-workflow/bridge-geometry-stg/roadway-alignment-stg).
{% endhint %}

## Steps

### Step 1: Navigate to Roadway Alignment

Navigate to **Bridge Geometry > Roadway Alignment** in the tree view.

![Roadway Alignment navigation](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-092800.png?api=v2)

### Step 2: Set Start Station

Enter **Start Station** as **0**.

### Step 3: Open Alignment Editor

Click the **three-dot icon** on the cell and select **Editor**.

![Alignment editor](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-103131.png?api=v2)

### Step 4: Add Horizontal Curve

Click the **+** icon next to **Horizontal** to add a circular segment.

![Add horizontal segment](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-103631.png?api=v2)

### Step 5: Enter Curve Parameters

Enter the following parameters:

* **Length:** 520 feet
* **Radius:** 700 feet
* **Direction:** Towards Right

![Curve parameters](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-104545.png?api=v2)

<details>

<summary><strong>Quick Tip:</strong> Vertical Alignment</summary>

Modify vertical data (grades and elevations) in the **Vertical** tab. In this example, vertical data is set to 0.

![Vertical tab](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-105031.png?api=v2)

</details>

### Step 6: Define Start Cross-Section

Click the **+** icon next to **Transverse** to add a cross-section at Station 0.

![Transverse section](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-105400.png?api=v2)

### Step 7: Enter Station 0 Parameters

Enter the following:

* **Station:** 0 ft
* **Left Edge to PGL:** 20 ft

![Station parameters](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-110703.png?api=v2)

### Step 8: Add Section Component

Click the **+** icon next to **At Sta+0** to add a section component with:

* **Width:** 40 ft
* **Slope:** -5%

![Section component](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-111508.png?api=v2)

![Width and slope](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-111544.png?api=v2)

### Step 9: Define End Cross-Section

Add another transverse section at Station 520:

* **Station:** 520 ft
* **Left Edge to PGL:** 20 ft
* **Width:** 40 ft
* **Slope:** -5%

![End station](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-113710.png?api=v2)

![End station parameters](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-113234.png?api=v2)

### Step 10: Accept Changes

Click **Accept** to save the alignment.

![Accept button](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-114659.png?api=v2)

<details>

<summary><strong>Quick Tip:</strong> Viewing Roadway Surface</summary>

If the 3D alignment doesn't appear, click **Zoom Extents** or enable **Show Roadway Surface** in Settings.

![Zoom extents](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-115004.png?api=v2)

![Show roadway surface](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-115226.png?api=v2)

</details>

## Verification

{% hint style="success" %}
The completed bridge alignment is shown below.
{% endhint %}

![Completed alignment](https://openbrim.atlassian.net/wiki/download/attachments/2168979464/image-20230216-144814.png?api=v2)
